If you love the nostalgic flavors of gooey s’mores but don’t want to build a campfire every time the craving hits, these S’mores Brownie Bars are about to become your new favorite dessert. They combine fudgy chocolate brownies, a buttery graham cracker crust, and toasted marshmallows—all baked conveniently in one pan.
This recipe takes everything you love about classic campfire s’mores and transforms it into a rich, crowd-pleasing dessert bar that’s perfect for parties, potlucks, holidays, or cozy nights at home. No fire pit required—just your oven and a little bit of patience while they bake.
Why You’ll Love These S’mores Brownie Bars
These bars are a guaranteed hit for several reasons:
- Classic flavors everyone loves – chocolate, marshmallow, and graham crackers
- Fudgy brownie texture with crisp edges and a soft center
- Easy to make in one pan – no fancy equipment needed
- Perfect for sharing – slices cleanly and travels well
- Great year-round dessert – summer nostalgia meets oven-baked comfort
They’re indulgent without being overly complicated, making them ideal for both beginner bakers and seasoned dessert lovers.
Ingredients
Graham Cracker Crust
- 1 ½ cups graham cracker crumbs (about 10 full sheets)
- ¼ cup granulated sugar
- ½ cup unsalted butter, melted
Brownie Layer
- 1 cup unsalted butter, melted
- 1 ¾ cups granulated sugar
- ¾ cup unsweetened cocoa powder
- 3 large eggs, room temperature
- 2 tsp vanilla extract
- 1 cup all-purpose flour
- ½ tsp salt
- ½ tsp baking powder
S’mores Topping
- 2 cups mini marshmallows
- ½ cup milk chocolate chips or chopped chocolate bars
- Optional: extra graham cracker pieces for topping
Step-by-Step Instructions
Step 1: Prepare the Pan
Preheat your oven to 350°F (175°C). Line a 9×13-inch baking pan with parchment paper, leaving an overhang on the sides for easy removal later. Lightly grease the parchment.
Step 2: Make the Graham Cracker Crust
In a medium bowl, mix the graham cracker crumbs, sugar, and melted butter until evenly combined. Press the mixture firmly into the bottom of the prepared pan to create an even crust.
Bake for 8–10 minutes, then remove from the oven and set aside while you prepare the brownie batter.
Tip: Press the crust firmly using the bottom of a measuring cup to help it hold together when sliced.
Step 3: Prepare the Brownie Batter
In a large bowl, whisk together melted butter and sugar until smooth. Add the cocoa powder and whisk until fully incorporated.
Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.
In a separate bowl, whisk together flour, salt, and baking powder. Gently fold the dry ingredients into the wet mixture just until combined. Do not overmix—this keeps the brownies fudgy.
Step 4: Assemble the Layers
Pour the brownie batter evenly over the pre-baked graham cracker crust. Smooth the top with a spatula.
Bake for 22–25 minutes, until the brownies are mostly set but still slightly soft in the center.
Step 5: Add the S’mores Topping
Remove the pan from the oven and immediately sprinkle chocolate chips evenly over the brownie layer, followed by the mini marshmallows.
Return the pan to the oven and bake for an additional 8–10 minutes, or until the marshmallows are puffed and lightly golden.
For extra toasted marshmallows, switch the oven to broil for 30–60 seconds—watch closely to avoid burning.
Step 6: Cool and Slice
Allow the bars to cool completely in the pan, then lift them out using the parchment paper. For clean slices, chill in the refrigerator for 30 minutes before cutting.
Slice into squares and serve.
Pro Tips for Perfect S’mores Brownie Bars
- Use good cocoa powder for deeper chocolate flavor
- Don’t overbake – slightly underbaked brownies stay fudgy
- Mini marshmallows work best for even coverage
- Chill before slicing for clean edges
- Line the pan with parchment to prevent sticking
Variations & Add-Ins
- Peanut Butter S’mores Bars: Swirl peanut butter into the brownie batter
- Dark Chocolate Version: Use dark chocolate chips for richer flavor
- Salted S’mores Bars: Sprinkle flaky sea salt on top before serving
- Cookie Base Option: Swap graham crackers for crushed chocolate cookies
Storage & Make-Ahead Tips
- Store bars in an airtight container at room temperature for up to 3 days
- Refrigerate for up to 5 days
- Freeze individually wrapped bars for up to 2 months
- Reheat briefly in the microwave for gooey marshmallows
Why This Recipe Works
This recipe layers texture and flavor perfectly:
- Crisp graham cracker crust
- Rich, fudgy brownie center
- Soft, toasted marshmallow topping
It captures the essence of classic s’mores while offering the convenience and consistency of a baked dessert—perfect for feeding a crowd.
Final Thoughts
These S’mores Brownie Bars bring together everything we love about summer campfires and homemade brownies in one irresistible dessert. They’re nostalgic, indulgent, easy to make, and guaranteed to disappear fast.
Whether you’re baking for a party, a family gathering, or simply because you’re craving chocolate and marshmallow goodness, this recipe delivers every single time.
🔥🍫 Campfire flavor—no campfire required.