Gooey Smores Cookie Bars

These gooey smores cookie bars feature a buttery graham cracker cookie dough, a thick layer of chocolate, and toasted, melted marshmallows.

Why This Recipe Works:

• Graham cracker flour replaces a portion of the all-purpose flour, infusing the cookie dough with that signature honey-spiced flavor without sacrificing structural integrity.
• A double-layer chocolate strategy using both milk chocolate bars and semi-sweet chips prevents the filling from turning rock-hard at room temperature.
• Broiling the marshmallow topping at the very end mimics the intense, direct thermal mass of a campfire, creating a caramelized crust while keeping the interior liquid-soft.

I still remember the exact July afternoon my cousin Sarah tried to toast a marshmallow over a gas stove burner using a wire coat hanger, only to drop the flaming mass directly onto my mother’s brand-new linoleum floor.

The smell of scorched plastic and burnt sugar lingered for days, but the desperate craving for that gooey, campfire-charred chocolate sandwich never truly left my bones.

Most s'mores bars are a structural disaster.

If you simply press graham cracker crumbs into a pan and throw chocolate on top, the base crumbles into dust the second your teeth sink in, while the marshmallows turn into a rubbery, tooth-chipping sheet of plaster once they cool down.

My solution is to fold finely ground graham crackers directly into a high-moisture cookie dough matrix, creating an absolutely perfect, bendable foundation that clings to the chocolate, even if pressing it into the pan feels a tad clumsy at first.

The base of this recipe is actually inspired by my love for a thick, chewy Giant Chocolate Chip Cookie, but with a heavy dose of nostalgia baked right in.

I used to make Fluffernutter Bars when I wanted a quick sweet fix, but these s'mores bars have officially taken over the top spot in my baking rotation.

If you prefer a classic cookie shape over a bar, you can try The Best Smores Cookies instead.

Trust me on this one, it completely changes the game.

Gooey Smores Cookie Bars

• Publisher Storied Skillet
• Cuisine American
• Category Dessert, Bars
• Prep Time 15 minutes
• Cook Time 25 minutes
• Servings 16
• Calories 320 calories
• Rating 4.8 2649
• Tags smores bars, cookie bars, graham cracker dessert, marshmallow chocolate bars

Ingredients

• 1/2 cup (113g) unsalted butter, melted and cooled slightly
• 1/2 cup (100g) packed light brown sugar
• 1/4 cup (50g) granulated sugar
• 1 large egg, room temperature
• 1 tsp vanilla extract
• 1 cup (120g) all-purpose flour
• 3/4 cup (85g) graham cracker crumbs (about 6 full sheets, finely ground)
• 1/2 tsp baking soda
• 1/2 tsp Diamond Crystal kosher salt
• 1 cup (170g) semi-sweet chocolate chips
• 2 milk chocolate bars (1.55 oz each), broken into rectangles
• 3 cups (150g) mini marshmallows

Directions

1. Preheat your oven to 350°F (175°C) and line an 8x8-inch metal baking pan with parchment paper, leaving an overhang on the sides for easy removal.
2. In a large bowl, whisk together the melted butter, light brown sugar, and granulated sugar until no lumps remain and the mixture looks glossy.
3. Whisk in the egg and vanilla extract vigorously until the mixture slightly pales and thickens, which helps build a strong protein matrix.
4. In a separate bowl, stir together the all-purpose flour, graham cracker crumbs, baking soda, and Diamond Crystal kosher salt.
5. Fold the dry ingredients into the wet ingredients using a rubber spatula just until a soft, fragrant dough forms.
6. Press about two-thirds of the cookie dough evenly into the bottom of your prepared pan, using your fingers to smooth it into the corners.
7. Scatter the semi-sweet chocolate chips and milk chocolate bar pieces evenly over the dough base.
8. Scatter the mini marshmallows over the chocolate layer, then dot the remaining cookie dough in small, flattened clumps over the top of the marshmallows.
9. Bake for 20 to 22 minutes until the exposed cookie dough is golden brown and the marshmallows are puffed and lightly toasted.
10. For that authentic campfire look, turn on the oven broiler for 1 to 2 minutes, watching like a hawk, until the marshmallow tops are deeply caramelized and charred in spots.
11. Allow the bars to cool completely in the pan for at least 1 hour before lifting them out using the parchment paper sling and slicing.
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Notes

• Salt Conversion: I always use Diamond Crystal kosher salt in my kitchen. If you are using standard fine table salt, cut the measurement in half (use 1/4 teaspoon instead of 1/2 teaspoon) to avoid an overly salty base.
• The Science of Graham Flour: Replacing a portion of the flour with graham cracker crumbs alters the gluten development. The bran in the graham crumbs physically cuts gluten strands, which guarantees a tender, melt-in-your-mouth cookie texture rather than a tough, bready bar.
• Watch the Broiler: Marshmallows transition from beautifully golden to a raging kitchen fire in a matter of five seconds. Do not walk away from the oven during the broiling step; keep your eyes glued to the oven window.
• Slicing Secret: These bars are incredibly sticky. To get clean cuts, wipe your knife blade with a warm, damp paper towel between every single slice to prevent the marshmallow from dragging.
• Storage Behavior: After a day in the fridge, the marshmallow layer will firm up significantly. If you prefer them warm and stretchy, pop a sliced bar into the microwave for 8 to 10 seconds before eating.

Serving Suggestions

These decadent bars are best enjoyed slightly warm when the chocolate is still melty, but they can also be dressed up for a backyard gathering.

• Serve warm with a generous scoop of vanilla bean ice cream to balance the rich chocolate.
• Drizzle with a bit of warm salted caramel sauce right before serving.
• Pair with a cold glass of milk or a strong, unsweetened iced coffee to cut through the sweetness.
• Dust the top lightly with a pinch of flaky sea salt to make the cocoa flavors pop.
• Cut them into tiny bite-sized squares for a party platter alongside our Strawberry Crunch Brownies.

Storage and Reheating

Let's be completely honest: keeping these bars at room temperature is a test of patience.

Store any leftover bars in an airtight container at room temperature for up to three days, separating layers with parchment paper so they do not fuse into one giant, sugary block.

If you put them in the fridge, the butter and chocolate will solidify, turning the soft cookie base into something resembling a brick.

Do not panic if that happens.

To restore them to their former glory, simply place a bar on a microwave-safe plate and heat it on high for 8 to 10 seconds, which instantly reactivates the oil-soluble flavor compounds and softens the marshmallow back to a gooey state.

Ingredient Substitutes

If you find yourself missing an ingredient, here are the best swaps that won't ruin the chemistry of your bake.

1. Graham Cracker Crumbs: If you cannot find graham crackers, digestive biscuits or Biscoff cookies work beautifully as a direct substitute. If you love cookie-butter flavors, you might also want to check out our Biscoff Butter Cookies.
2. Mini Marshmallows: You can use large marshmallows cut in half, or even a jar of marshmallow fluff swirled over the chocolate layer, though fluff will be slightly sweeter and spread more during baking.
3. Chocolate Bars: If you do not have milk chocolate bars, feel free to use high-quality milk chocolate chips or chopped dark chocolate chunks for a less sweet, more grown-up flavor profile.
4. Brown Sugar: Dark brown sugar can be used instead of light brown sugar, which will give the cookie base a deeper, more caramel-like molasses flavor.

I hope these bring a little bit of that messy, sticky, summer-camp magic into your kitchen, minus the actual smoke in your eyes and the inevitable mosquito bites. Let me know in the comments if you managed to let them cool before slicing, because I certainly didn't.