S’mores Cookie Bars with Chocolate and Marshmallow

Cut s’mores cookie bars showing graham cookie layers, melted chocolate, and marshmallow on a parchment-lined tray.

S’mores Cookie Bars combine a soft graham cracker cookie with melted chocolate and gooey marshmallow creme. A golden cookie topping makes them easy to slice and share, while every bite has the flavors of a classic s’more.

You can make these in an 8-inch square pan with no campfire or individual s’mores to assemble. Let the bars cool completely before cutting them so the chocolate and marshmallow layers have time to settle.

Why You’ll Love This Recipe

All the familiar flavors: Graham crackers, chocolate, and marshmallow come together in one bar.
Easy to share: One pan makes 16 dessert squares.
A soft cookie base: The graham crumbs give the dough flavor and a little texture.
A gooey center: Chocolate and marshmallow creme stay between the cookie layers.

Ingredients

For the graham cookie dough

¾ cup (170 g) unsalted butter
¾ cup (150 g) packed light brown sugar
¼ cup (50 g) granulated sugar
1 large egg
1 teaspoon vanilla extract
1 tablespoon milk
1¼ cups (150 g) all-purpose flour
1 cup (about 110 g) finely crushed graham crackers
½ teaspoon baking powder
½ teaspoon fine salt

For the filling

6 ounces (170 g) semisweet chocolate, chopped into small pieces
One 7-ounce jar marshmallow creme

If you love layered chocolate desserts, make my Oreo Brookies next.

How to Make S’mores Cookie Bars

Prepare the Pan and Brown the Butter

First, heat the oven to 350°F. Line an 8-inch square baking pan with parchment paper, leaving enough overhang on two sides to lift out the cooled bars.

Next, melt the butter in a light-colored saucepan over medium heat. Stir or swirl it frequently. Once the milk solids turn golden brown and the butter smells nutty, pour it into a heatproof bowl. Include the browned bits, then let the butter cool for about 15 minutes, until it feels warm rather than hot.

Make the Graham Cookie Dough

Whisk the brown sugar and granulated sugar into the cooled butter. Then add the egg, vanilla, and milk, and whisk until combined.

In a separate bowl, stir together the flour, graham cracker crumbs, baking powder, and salt. Add the dry ingredients to the butter mixture and stir just until a soft dough forms.

Add the Chocolate and Marshmallow

Press about two-thirds of the dough evenly into the lined pan. Sprinkle the chopped chocolate over the base. Spoon the marshmallow creme in small dollops over the chocolate, then gently spread it across the pan.

Flatten small pieces of the remaining dough between your fingers and arrange them over the filling. Leave a few gaps so the chocolate and marshmallow can show through.

Bake and Cool

Bake for 28–33 minutes, until the cookie topping is golden and the center no longer looks like raw dough. If exposed marshmallow starts browning too quickly, loosely cover the pan with foil for the rest of the bake time.

Finally, let the bars cool completely in the pan for at least 2 hours. Lift them out with the parchment and cut into 16 squares. Wipe the knife between cuts for cleaner edges.

Tips for the Best S’mores Cookie Bars

Use finely crushed graham crackers. Small, even crumbs mix into the cookie dough more easily than large pieces.

Choose chopped chocolate for a visible layer. Chopped chocolate creates pockets of melted chocolate when the bars are cut.

Leave gaps in the topping. The top dough does not need to cover every bit of filling. Those openings let the marshmallow

and chocolate show. Wait before slicing. The bars are very soft when warm. Cooling gives the layers time to set.

How to Serve S’mores Cookie Bars

Serve the bars at room temperature when you want neat squares. For a softer, gooier dessert, warm an individual bar briefly before serving. They also pair well with a glass of milk or a scoop of vanilla ice cream.

FAQ

Can You Freeze S’mores Cookie Bars?

For longer storage, wrap fully cooled, cut bars individually and place them in a freezer-safe container for up to 2 months. Thaw them in the refrigerator, then bring them to room temperature before serving. Because the marshmallow texture may change after freezing, check this result during your kitchen test before adding the freezing advice to the live post.

Recipe Card

Yield: 16 bars
Prep time: About 35 minutes
Bake time: 28–33 minutes
Cooling time: At least 2 hours
Total time: About 3 hours 5 minutes
Pan: 8 × 8 inches
Oven: 350°F

More Cookie Recipes to Try

If you like chocolate-filled desserts, try my Marry Me Cookies next. They have brown butter, oats, and two kinds of chocolate.