Irresistible S’mores Cookie Bars: The Ultimate Gooey, Chewy Treat with Marshmallow Frosting
As an avid baker and someone frequently on “dessert duty,” I’ve whipped up countless s’mores creations over the years. From the traditional campfire classic to chewy s’mores cookies with marshmallow centers and even gooey s’mores cinnamon buns with a graham cracker crust, my kitchen has seen it all. But among all these delightful variations, these S’mores Cookie Bars truly stand out as my absolute go-to recipe. They are incredibly easy to assemble, consistently deliver a show-stopping dessert, and capture the nostalgic essence of s’mores in every single bite.
What truly makes these S’mores Cookie Bars so special? It’s the perfect harmony of textures and flavors that work together to create an unforgettable treat. You start with a wonderfully soft, buttery, and chewy graham cracker cookie dough base, which provides that authentic s’mores crunch and delightful flavor in a more refined form. Layered within this delightful cookie is a thick, rich, and utterly gooey chocolate filling that melts in your mouth with every bite, delivering a decadent experience. And to crown it all, there’s a cloud-like marshmallow creme frosting. This isn’t just any frosting; it’s wonderfully plush and creamy, yet sets just enough to allow for beautifully clean slices, making it ideal for sharing at any gathering (or, let’s be honest, for enjoying all by yourself!).
These S’mores Cookie Bars are more than just a dessert; they’re a celebration of summer, warmth, and pure indulgence. Their ease of preparation and the universal appeal of s’mores make them perfect for any occasion. Whether you’re hosting a backyard barbecue, looking for a treat for a picnic, or simply craving a taste of nostalgia, these bars are a guaranteed crowd-pleaser. They’re the kind of treat that disappears quickly, leaving everyone craving “just one more piece.” Simple to prepare and bursting with classic s’mores flavor, they’re destined to become your favorite summer dessert bar, perfect for enjoying all season long and beyond!
Why These S’mores Cookie Bars Are a Must-Try Dessert
There are countless reasons to fall head over heels for these S’mores Cookie Bars, but a few key elements make them truly exceptional and a superior alternative to traditional s’mores. Firstly, the convenience factor is unmatched. While traditional s’mores require a campfire, sticky fingers, and often a bit of a mess, these bars bring all those beloved flavors indoors in a portable, easy-to-handle format. You get all the nostalgic goodness without any of the fuss, making them perfect for picnics, potlucks, school events, or simply enjoying at home. No sticky cleanup, no burnt marshmallows (unless you intentionally toast the frosting, which is a fantastic optional customization!).
Beyond convenience, the texture profile of these bars is pure perfection. The cookie base isn’t just a basic crust; it’s a soft, rich, buttery, and distinctly graham cracker-flavored cookie that provides a satisfying chewiness and structure. This isn’t a crumbly, dry base – it’s a foundational layer that’s integral to the overall s’mores cookie bar experience. Then, the chocolate layer is designed to be deeply fudgy, wonderfully melty, and incredibly gooey, giving you that delightful, stretchy pull when you take a bite. It’s a rich dark or semi-sweet chocolate that complements the sweetness of the other layers. Finally, the marshmallow creme frosting delivers a light, airy, and fluffy sweetness that perfectly balances the rich chocolate and hearty cookie. This particular frosting is key because it stays plush but sets, allowing for beautifully clean slices, sealing the deal on an unforgettable dessert. It’s truly an elevated, yet simple, take on a beloved classic, ensuring a delightful experience for everyone.
How to Make Them: A Step-by-Step Guide to Perfect S’mores Bars
Crafting these delicious S’mores Cookie Bars is a straightforward process, but paying attention to each step ensures a perfect outcome every time. Here’s a detailed breakdown:
1
Make the graham cracker cookie dough. This delightful dough forms the foundation of your s’mores bars. It comes together surprisingly quickly in a stand mixer. You’ll be left with a soft, buttery mixture that’s generously packed with finely ground graham cracker crumbs, ensuring every bite carries that unmistakable classic s’mores flavor. Remember to use room temperature butter and egg for the best, most uniform dough consistency, which is key for a soft and chewy cookie. Creaming the butter and sugar thoroughly creates air pockets for a lighter texture.
2
Spread half of the graham cracker cookie base into an 8×8 baking pan. Once your dough is ready, divide it equally. Carefully press one half of the dough into an even layer in your prepared 8×8 baking pan, which should be lined with parchment paper. After pressing, lift this entire dough layer out of the pan using the parchment paper and transfer it to a flat surface like a plate or cutting board. Immediately pop this first layer into the fridge. This initial chilling step helps the dough maintain its shape and texture during baking, preventing excessive spreading and ensuring a distinct bottom layer.
3
Reline the pan and spread the remaining dough into it. Now, reline your baking pan with a fresh piece of parchment paper. Take the remaining half of your graham cracker cookie dough and evenly spread it into the bottom of this newly lined pan. This will form the top cookie layer of your s’mores bars. Put both layers—the one currently in the pan and the one on the plate from step 2—into the fridge to chill for a full 30 minutes. This combined chilling process is absolutely essential as it prevents the cookies from spreading too much during baking and ensures a perfectly sturdy yet tender base and top with a beautiful, even layer.
4
Make the chocolate filling. While your cookie dough is chilling in the fridge, take this time to prepare the luscious chocolate filling. This rich mixture should be wonderfully thick and glossy, with a consistency that’s quite similar to a decadent brownie batter. The key is to melt the chocolate chips and butter gently, ensuring a smooth base, and then whisk in the remaining ingredients until they are all well-combined and velvety. This step ensures a perfectly gooey and irresistible chocolate center for your s’mores bars.
5
Spread the chocolate filling. With your cookie dough chilled and your decadent chocolate filling ready, it’s time to layer! Retrieve the bottom cookie layer that’s in the baking pan from the fridge. Pour the warm, rich chocolate filling evenly over this chilled cookie base. Use a spatula to gently spread it out, ensuring it creates a uniform and decadent layer from edge to edge. This forms the incredibly gooey and flavorful heart of your s’mores cookie bars.
6
Add the top cookie layer. Now it’s time to cap off your s’mores bars! Retrieve the second chilled dough layer from the fridge. Carefully peel off the parchment paper that was used for chilling. Gently place this dough layer upside down (so the flat, smooth side is facing up) directly over the chocolate filling. Press down very lightly to ensure it adheres to the chocolate layer without compressing the dough too much. This careful placement ensures your s’mores bars will have a beautiful, even top once baked, sealing in all that delicious chocolatey goodness.
7
Bake the s’mores bars until the edges are golden brown and the top is puffy and set. Place the pan in your preheated oven and bake for the recommended time. You’ll know they’re perfectly baked when the edges have turned a beautiful golden brown and the top appears puffy and set. The center might look slightly blotchy or softer, which is perfectly normal and actually indicates a wonderfully gooey chocolate core. It should look soft and matte, not wet or overly shiny. Avoid overbaking, as this will prevent that desirable chewy texture. Once baked, remove the pan from the oven and transfer it to a wire rack. Let the bars cool completely at room temperature for several hours (ideally 2-3 hours), or until they are firm and cool to the touch. This extended cooling time is absolutely crucial for the chocolate layer to set properly, ensuring clean slices later.
8
Frost and slice. The grand finale! Once the s’mores bars are completely cool (this is absolutely crucial for clean and neat cuts), it’s time to prepare the fluffy and irresistible marshmallow frosting. Spread this creamy frosting generously and evenly over the top of the cooled bars. Allow the icing to set at room temperature for approximately 30 minutes, or until it’s firm enough not to stick to your knife when slicing. For truly clean, professional-looking edges, use a sharp knife. Run it under hot water and meticulously wipe it clean between each individual cut. This clever trick prevents the frosting and chocolate from dragging, ensuring every one of your 15 irresistible s’mores cookie bars looks as good as it tastes. Feel free to sprinkle with extra graham cracker crumbs for a final touch of visual appeal and added flavor.
Tips for S’mores Cookie Bar Success: Achieving Perfection Every Time
Achieving bakery-quality s’mores cookie bars is easier than you think, especially with a few simple but crucial baking tips. Follow these guidelines to ensure your bars turn out perfectly soft, chewy, and gooey with distinct layers:
- Measure Dry Ingredients Properly: This is arguably the most important baking tip for any recipe, and especially for cookies and bars! Avoid the common mistake of scooping your measuring cup directly into flour, as this compacts it and invariably leads to using too much flour, which can result in dry, dense bars. Instead, use the spoon-level method: fluff the flour with a fork or whisk first, then spoon it gently into your measuring cup until overflowing, and finally, level it off with a straight edge (like the back of a knife). For the most accurate and consistent results, I highly recommend using a digital kitchen scale – it truly makes a difference in baking precision!
- Room Temperature Ingredients Are Key: Ensure that your unsalted butter and large egg for the graham cracker cookie dough are at room temperature. This allows them to cream together smoothly and evenly with the powdered sugar, creating a uniform, well-emulsified dough. Cold ingredients don’t blend as well, leading to a lumpy batter and potentially inconsistent baking.
- Do Not Overbake: Keep a close eye on your s’mores bars as they bake. Overbaking is the enemy of chewy, gooey desserts! Overbaked bars can lead to dry, crumbly cookies and a less melty, fudgy chocolate center. The edges should be lightly golden brown, and the center should look set but still appear slightly soft and matte (not wet or shiny). Remember, they will continue to set as they cool.
- Chill the Dough Thoroughly: The chilling steps for both layers of the graham cracker cookie dough are non-negotiable. This crucial step prevents the dough from spreading too much in the oven, ensuring you get distinct, beautifully layered, and wonderfully chewy cookie layers rather than a flat, amorphous mass. Don’t skip this step – it’s worth the wait!
- Cool Completely Before Frosting and Slicing: Patience truly is a virtue when it comes to these bars! Attempting to frost or slice them while they are still warm will inevitably result in a messy, gooey disaster. The chocolate filling needs ample time to set, and the bars need to firm up to hold their shape. Allow them to cool completely on a wire rack for at least 2-3 hours, or even longer if your kitchen is warm. This will ensure clean, precise, and beautiful slices.
- The Hot Knife Trick for Perfect Slices: For perfectly clean, professional-looking slices, use a sharp knife. Before each cut, dip your knife into hot water and thoroughly wipe it dry with a paper towel. This prevents the marshmallow frosting and gooey chocolate from sticking to the blade and dragging, giving you beautifully defined bars every single time.
Customization & Variations for Your S’mores Cookie Bars
While the classic S’mores Cookie Bar recipe is absolutely divine on its own, don’t hesitate to get creative and customize your batch with these delightful variations:
- Experiment with Chocolate Choices: The chocolate filling is a star, so feel free to experiment! Instead of just dark or semi-sweet chocolate chips, try a mix of milk chocolate for a sweeter profile, white chocolate chips for a different flavor dimension, or even chopped up pieces of your favorite gourmet chocolate bar for added complexity and texture. A sprinkle of mini chocolate chips on top before baking or after frosting also adds a lovely visual and textural element.
- Add Extra Crunch and Flavor: Introduce another layer of texture by folding in some chopped nuts (pecans or walnuts work exceptionally well) into the chocolate filling or sprinkling them over the top. For an even more pronounced graham cracker flavor and crunch, crumble extra graham cracker pieces and scatter them over the marshmallow frosting before it sets.
- Achieve Toasted Marshmallow Perfection: If you’re yearning for that authentic campfire char, you can lightly toast the marshmallow frosting after spreading it. The easiest way to do this is with a kitchen torch, carefully browning the peaks of the frosting for a beautiful golden hue and a smoky flavor. Alternatively, you can place the pan under a broiler for a minute or two, but watch it very carefully to prevent burning, as marshmallow can char quickly!
- Embrace Seasonal Twists: Adapt these bars for different seasons. In the fall, a hint of pumpkin spice or cinnamon in the graham cracker cookie dough can transform them into a cozy autumn treat. For a festive winter touch, consider using mint chocolate chips in the filling for a refreshing twist.
- Candy Bar Mix-Ins: Chop up some of your favorite candy bars (like peanut butter cups or caramel pieces) and fold them into the chocolate filling or sprinkle them on top of the bottom cookie layer before adding the chocolate. The possibilities are endless!
Storage and Make-Ahead Instructions for Convenience
These S’mores Cookie Bars are fantastic for making ahead and storing, making them an ideal choice for parties, meal prep, or when you simply want to enjoy a sweet treat throughout the week without extra effort. Proper storage ensures they maintain their delicious texture and flavor.
- Standard Storage: To keep your leftover s’mores bars fresh and delicious, store them in an airtight container at room temperature for up to 3-4 days. While refrigeration can extend their shelf life, it might alter the texture of the cookie base slightly, making it a bit firmer and less chewy. If you do choose to refrigerate them, I recommend letting them come closer to room temperature for about 15-30 minutes before serving for the best gooey chocolate experience and softer cookie.
- Freezing for Longer Freshness: These bars freeze wonderfully, both frosted and unfrosted!
- Unfrosted Bars: If you plan to freeze them without frosting, ensure the baked bars are completely cool. Wrap them tightly in plastic wrap, then an additional layer of aluminum foil to prevent freezer burn. They will keep well in the freezer for up to 1 month. When ready to serve, thaw them at room temperature for a few hours, then prepare and apply the fresh marshmallow frosting as directed in the recipe.
- Frosted Bars: To freeze frosted bars, first place the whole pan (or individual cut bars) on a baking sheet and flash freeze them for about 1-2 hours until the marshmallow frosting is completely solid. This prevents the frosting from sticking to the wrapping. Once solid, wrap each individual bar tightly in plastic wrap, followed by a layer of aluminum foil. They can be stored in the freezer for up to 3 weeks. Thaw at room temperature for a few hours before indulging.
- Make-Ahead Dough: To streamline your baking process, the graham cracker cookie dough can be prepared a day in advance. Simply follow the dough preparation steps, form the two layers, and keep them tightly wrapped in plastic wrap in the refrigerator. This can significantly save you time on baking day, allowing for fresh, warm s’mores bars with minimal effort.
Already halfway to licking the pan clean? Same here! These S’mores Cookie Bars are truly addictive and designed to bring joy with every bite. But if you’re anything like me and always ready to double down on the s’mores love and explore another incredible variation, I highly recommend trying my s’mores brownies with homemade marshmallow next. They’re exceptionally rich, wonderfully chewy, and packed with that deep, gooey, toasty goodness that makes you go back for one more bite, every single time. Happy baking and even happier eating!
If you tried this recipe or any other recipe on my website, please let me know how it went in the comments; I love hearing from you! Also, please leave a star rating while you’re there! You can also tag me on Instagram or Facebook so I can check it out!
S’mores Cookie Bars with Marshmallow Frosting
Print Recipe
Save RecipeSaved!
Pin Recipe
Equipment
-
square 8×8 metal baking pan
Ingredients
Graham Cracker Cookie Crust
- 1 cup unsalted butter, room temperature
- 1 1/4 cup powdered sugar
- 1 large egg, room temperature
- 1 teaspoon vanilla paste or extract
- 1 1/2 cups all-purpose flour, *See notes below for measuring*
- 1 cup finely ground graham cracker crumbs
- 1/2 teaspoon fine sea salt
Chocolate Filling
- 3/4 cup dark or semi-sweet chocolate chips
- 1/4 cup unsalted butter
- 1 large egg
- 1/4 cup brown sugar, packed
- 1 teaspoon vanilla
- 1 tablespoon cocoa powder
- 1/4 teaspoon fine sea salt
Marshmallow Frosting
- 3.5 ounces marshmallow creme
- 1.5 ounces cream cheese, softened
- 1/4 cup heavy cream
- 1 teaspoon vanilla paste
- Graham cracker crumbs, for topping
Instructions
-
Begin by preparing your baking pan. Line an 8×8 metal baking pan with a sheet of parchment paper, ensuring it covers all four sides and overhangs slightly on two opposite sides. This overhang will serve as handles for easy lifting of the baked bars later. Set the prepared pan aside.
-
In the bowl of a stand mixer fitted with the paddle attachment (or using a hand mixer with a large bowl), combine the room temperature unsalted butter and powdered sugar. Begin by pulsing the mixer on low speed for a few seconds; this prevents the powdered sugar from creating a mess and flying everywhere. Once initially combined, increase the speed to medium and cream them together until the mixture is light, fluffy, and pale in color, typically taking 2-3 minutes. Scrape down the sides of the bowl as needed.1 cup (219 g) unsalted butter, 1 1/4 cup (150 g) powdered sugar
-
Once the butter and sugar are perfectly creamed, add the large room temperature egg and vanilla paste (or extract). Mix on medium speed until everything is thoroughly incorporated and the mixture appears smooth. Finally, gently fold in the all-purpose flour, finely ground graham cracker crumbs, and fine sea salt using a spatula or by mixing on low speed until just combined. Be careful not to overmix the dough, as this can lead to tough bars.1 (50 g) large egg, 1 teaspoon (4 g) vanilla paste or extract, 1 1/2 cups (190 g) all-purpose flour, 1 cup (100 g) finely ground graham cracker crumbs, 1/2 teaspoon fine sea salt
-
Divide the prepared cookie dough exactly in half (each portion should be approximately 345 grams for accuracy, if you’re using a kitchen scale). Press one half evenly into the bottom of your prepared 8×8 baking pan, creating a smooth and uniform layer. Then, using the parchment paper handles, carefully lift this dough layer out of the pan and transfer it to a flat surface (like a plate or cutting board). Set this layer aside in the fridge to chill. Re-line the empty baking pan with a fresh piece of parchment paper in the same manner, and then evenly spread the remaining half of the dough into the bottom of this newly lined pan. Chill both dough layers (one on the plate, one in the pan) in the fridge for a minimum of 30 minutes. This is crucial for preventing the dough from spreading too much during baking and achieving distinct, chewy layers.
-
While the cookie dough chills, preheat your oven to 325°F (160°C). Ensure your oven is at the correct temperature before proceeding with the next steps.
-
Next, prepare the decadent chocolate filling. In a microwave-safe bowl, combine the dark or semi-sweet chocolate chips and unsalted butter. Microwave in 30-second intervals, stirring well after each, until the mixture is completely melted and smooth. Alternatively, you can melt them in a double boiler over simmering water. Once melted, whisk in the large egg, packed brown sugar, and vanilla until well combined and glossy. Finally, whisk in the cocoa powder and fine sea salt until the mixture is thick, smooth, and resembles a rich brownie batter in consistency.3/4 cup (150 g) dark or semi-sweet chocolate chips, 1/4 cup (56 g) unsalted butter, 1 (50 g) large egg, 1/4 cup (50 g) brown sugar, 1 teaspoon (2 g) vanilla, 1 tablespoon (12 g) cocoa powder, 1/4 teaspoon fine sea salt
-
Remove both chilled cookie dough layers from the fridge. Carefully pour the prepared chocolate filling over the bottom cookie layer that is in the baking pan, using an offset spatula or the back of a spoon to spread it evenly to completely fill the pan’s surface. Then, delicately remove the parchment paper from the second chilled dough layer (the one that was on the plate). Invert it and carefully place it flat-side down directly on top of the chocolate filling. Press very gently to ensure it adheres without compressing the dough too much.
-
Bake the s’mores bars in your preheated oven for approximately 40-45 minutes. You’ll know they’re ready when the edges are beautifully golden brown and the top appears puffy and set. The center might look slightly blotchy or softer, which is perfectly normal and actually indicates a wonderfully gooey chocolate core. It should look soft and matte, not wet or overly shiny. Avoid overbaking, as this will prevent that desirable chewy texture. Once baked, remove the pan from the oven and transfer it to a wire rack. Let the bars cool completely at room temperature for at least 2-3 hours, or until they are firm and cool to the touch. This extended cooling time is absolutely crucial for the chocolate layer to set properly, ensuring clean slices.
-
To create the irresistible marshmallow icing, combine the marshmallow creme and softened cream cheese in a medium bowl. Stir them together vigorously with a spoon or spatula until the mixture is smooth and well-blended. Ensure there are no lumps from the cream cheese. Then, gradually whisk in the heavy cream and vanilla paste until the frosting is light, fluffy, and completely smooth. The consistency should be spreadable but hold its shape.3.5 ounces marshmallow creme, 1.5 ounces cream cheese, 1/4 cup heavy cream, 1 teaspoon vanilla paste
-
Once the s’mores bars are completely cool to the touch, spread the prepared marshmallow icing generously and evenly over the top, creating a smooth, fluffy layer. Allow the icing to set at room temperature for approximately 30 minutes, or until it’s firm enough not to stick excessively to your knife when slicing. For an extra touch of s’mores authenticity and visual appeal, you can sprinkle additional graham cracker crumbs over the top just before serving.Graham cracker crumbs
-
Finally, use a sharp knife to cut the bars into 15 perfect squares. To achieve the cleanest possible edges, a trick professional bakers use is to run the knife under hot water and meticulously wipe it clean with a paper towel between each individual cut. This clever technique prevents the frosting and gooey chocolate from dragging, ensuring every one of your irresistible s’mores cookie bars looks as appealing and tidy as it tastes. Serve and enjoy!
Notes
Storage: Keep leftovers in an airtight container at room temperature for 3-4 days. For extended freshness and freezing options, refer to the “Storage and Make-Ahead Instructions” section above for detailed guidance.
The calorie information provided for the recipe is an estimate. The accuracy of the calories listed is not guaranteed.