These Chocolate Chip Marshmallow Cookie Bars are a delicious s’mores-inspired twist on a classic treat. With a base made from graham cracker cookie dough, gooey toasted marshmallows, and melty chocolate chips on top, they recreate the nostalgic campfire flavor—no smoke or fire pit required. Browning the butter gives extra depth to the bars, while baking in a pan eliminates any cookie spread issues. Perfect for sharing or indulging solo with a tall glass of milk.

Full Recipe: 

Ingredients

For the Bars:

• ⅔ cup (151g) unsalted butter, plus more for greasing pan

• 6 whole graham crackers (90g), pulverized

• ⅖ cup (83g) all-purpose flour

• ½ tsp salt

• ½ tsp baking powder

• ¼ tsp baking soda

• ½ cup (96g) dark brown sugar

• 1 large egg

• 1 egg yolk

• ½ tsp vanilla extract

• 8 oz semisweet or bittersweet chocolate chips

Topping:

• 2 whole graham crackers, broken into pieces

• 1 cup mini marshmallows

• 4 oz semisweet or bittersweet chocolate chips

Directions

1. Preheat oven to 325°F. Grease an 8- or 9-inch square pan.

2. Brown the butter over medium-low heat, stirring until it smells nutty and the bubbling stops. Remove from heat to cool.

3. Pulverize graham crackers and add to a medium bowl.

4. Sift together flour, salt, baking powder, and baking soda into the graham cracker crumbs and whisk to combine.

5. In another bowl, mix brown sugar and browned butter.

6. Add egg and egg yolk, beat for 1 minute. Add vanilla and beat another minute.

7. Stir in dry ingredients by hand, then fold in 8 oz chocolate chips.

8. Spread evenly in the pan and bake 25–30 minutes until browned and pulling from the sides. A toothpick should come out clean.

9. Set oven to broil. Top the bars with graham cracker pieces and marshmallows. Broil for 45–60 seconds until marshmallows are golden (watch closely).

10. Remove from oven, sprinkle remaining 4 oz chocolate chips over top, and cover with foil for 5–10 minutes to melt.

11. Cool and cut into 16 squares.

Nutrients (Per bar, approx.)

• Calories: 276 kcal

• Carbohydrates: 29g

• Protein: 3g

• Fat: 17g

• Saturated Fat: 10g

• Sugar: 17g

• Fiber: 2g

• Sodium: 167mg

• Cholesterol: 44mg

A Textural Masterpiece in Every Bite

What sets these cookie bars apart is their deliberate layering of textures. The base is a dense, chewy graham cracker-laced cookie dough that anchors the entire bar. The inclusion of brown butter in the dough gives it a rich, nutty aroma and depth, enhancing the overall flavor far beyond a traditional cookie base. As the bars bake, the cookie layer sets just enough to hold its shape but remains soft and tender in the center.

The marshmallow topping is broiled briefly to achieve that signature golden, toasty exterior while keeping the insides gooey and molten. It’s the key to capturing the unmistakable feel of roasted marshmallows without ever lighting a fire. Finally, semisweet or bittersweet chocolate chips are sprinkled over the top after baking, then gently melted under foil to create pools of velvety chocolate that echo the melted squares of a classic s’more.

The Role of Brown Butter in Elevating Flavor

One of the defining characteristics of this recipe is the use of browned butter in the base. Browning butter not only changes its color, but it also deepens the flavor by caramelizing the milk solids. This process introduces notes of toffee, hazelnut, and butterscotch—flavors that harmonize beautifully with graham cracker and chocolate. When incorporated into cookie dough, browned butter lends a complexity and warmth that sets these bars above other s’mores-style desserts.

This extra step requires only a few minutes but makes a world of difference, creating a nutty aroma that’s evident from the moment the bars begin to bake. It’s one of those small enhancements that delivers an outsized impact on the final flavor.

No Campfire Required: Convenience and Consistency

While traditional s’mores require fire and a certain amount of outdoor orchestration, these cookie bars bring the same flavor and spirit to your kitchen in a far more consistent and manageable form. Baking them in a pan eliminates issues like cookie spread or uneven doneness—common pitfalls in drop cookies. Plus, they’re easy to transport, slice cleanly, and don’t require any assembly before serving.

This makes them a perfect candidate for entertaining, potlucks, or school functions. They hold up well at room temperature and stay soft for days when stored properly. You can make them ahead, slice them cleanly once cooled, and present them as bite-sized pieces of gourmet comfort food.

Versatile and Customizable

Another benefit of these bars is how easily they adapt to your preferences. If you prefer milk chocolate over bittersweet, or want to use chocolate chunks instead of chips, the recipe accommodates those swaps effortlessly. Want to add nuts, coconut, or a swirl of peanut butter? Go ahead—this recipe provides a sturdy, forgiving base for all sorts of flavor combinations.

For a more decadent finish, some bakers drizzle the bars with additional melted chocolate or even a touch of caramel sauce before serving. You can also swap mini marshmallows for large ones cut into smaller pieces, or even flavored marshmallows for a fun twist. However you personalize it, the result remains a layered dessert that delivers both visual appeal and deep, toasty flavor.

Kid-Friendly but Grown-Up Approved

These bars are designed to appeal to all ages. Kids are drawn in by the gooey marshmallows and sweet chocolate, while adults appreciate the nuanced layers of flavor created by the browned butter and graham base. They’re sweet without being cloying, and the balance between the marshmallow and chocolate ensures every bite feels rich and satisfying but never overwhelming.

They’re a great recipe to make with children too, especially when it comes to placing the graham cracker pieces and marshmallows on top. Watching the marshmallows toast under the broiler is a rewarding, visually exciting step that connects kids to the final product in a hands-on way.

Perfect Occasions to Serve These Bars

Whether you’re planning a picnic, a birthday party, a summer barbecue, or a holiday cookie exchange, these cookie bars fit the mood. They’re equally at home in a casual lunchbox as they are plated on a dessert buffet. Their square format also makes them ideal for portion control, especially when you slice them into smaller squares for large gatherings.

Because they evoke a classic dessert with wide nostalgic appeal, they also serve as a conversation starter—an updated twist on a beloved campfire memory that instantly resonates with anyone who’s ever toasted a marshmallow.

Storage and Make-Ahead Tips

These bars store well at room temperature for 3 to 4 days in an airtight container. If you prefer them slightly warm, you can microwave individual squares for 10–15 seconds to re-melt the chocolate and soften the marshmallows. They also freeze beautifully. Wrap individual pieces in plastic wrap and store in a freezer-safe container. When ready to serve, let them thaw at room temperature for about 20 minutes, or microwave briefly to enjoy them warm.

For make-ahead prep, you can also bake the base layer a day in advance, then broil and finish with the toppings just before serving. This strategy ensures the marshmallows remain fluffy and toasted at the moment of presentation.

Conclusion

Chocolate Chip Marshmallow Cookie Bars are a delicious, fun, and elevated take on a classic dessert that never goes out of style. With their graham cracker cookie base, toasty marshmallow top, and luscious melted chocolate chips, they deliver all the satisfaction of a s’more in a more elegant, shareable format. Browned butter adds richness and depth, transforming them from a nostalgic nod into a gourmet-worthy treat. Easy to make, endlessly customizable, and perfect for any crowd, these bars are a must-bake for anyone who loves sweet comfort food with a little bit of flair. Whether served at a casual party or enjoyed quietly with a glass of milk, they offer warmth, nostalgia, and indulgence in every bite.