Food and Recipes Desserts Cakes Sheet Cakes S'mores Chocolate Sheet Cake 5.0 (2) Add your rating & review Our favorite summertime treat in sheet cake form—no campfire required! By Molly Bolton Molly Bolton Molly Bolton is a self-taught home baker, recipe developer, and food photographer located in Birmingham, Alabama. She has 3+ years of experience creating and capturing original, trustworthy recipes designed for the home baker. Southern Living's editorial guidelines Published on May 26, 2023 Rate PRINT Share Close Photo: Molly Bolton Active Time: 45 mins Total Time: 2 hrs 30 mins Servings: 18 This S’mores Chocolate Sheet Cake has all the delicious flavors of a gooey, chocolatey s’mores, but without the campfire. Moist chocolate sheet cake topped with a layer of decadent chocolate ganache that’s covered in a smooth marshmallow buttercream frosting and toasty graham cracker crumbs. Easy to make and even easier to share! Molly Bolton Ingredients Toasted Graham Cracker Topping 3 graham cracker sheets, crushed into crumbs 1 Tbsp. granulated sugar 1 Tbsp. unsalted butter, melted 1/2 tsp. vanilla extract 1/8 tsp. kosher salt Chocolate Cake Cooking spray 2 cups all-purpose flour 3/4 cup unsweetened cocoa powder 2 cups granulated sugar 1 tsp. baking powder 2 tsp. baking soda 1/2 tsp. kosher salt 2 tsp. espresso powder or instant espresso granules 3/4 cup whole buttermilk, at room temperature 1/2 cup sour cream, at room temperature 1/2 cup vegetable oil 2 large eggs, at room temperature 2 tsp. vanilla extract 3/4 cup hot coffee Chocolate Ganache 1 (4 oz.) bar semisweet chocolate, finely chopped 1/2 cup heavy cream Marshmallow Buttercream Frosting 1 cup (8 oz.) unsalted butter, softened 3 cups powdered sugar, sifted 1 Tbsp. vanilla extract 2 (7 oz.) containers marshmallow crème Directions Make the Toasted Graham Cracker Topping: Preheat the oven to 300°F and line a rimmed baking sheet with parchment paper; set aside. Gather your ingredients. Molly Bolton Add the graham cracker crumbs, sugar, melted butter, vanilla extract and kosher salt to a small bowl and stir to combine. Molly Bolton Arrange the graham cracker crumbs in a single layer on the prepared baking sheet. Bake until lightly toasted and fragrant, about 7 to 8 minutes. Set aside to cool. Molly Bolton Prepare the Chocolate Cake: Increase the oven temperature to 350°F. Generously grease a 9- x 13-in. baking pan with cooking spray; set aside. In the bowl of a stand mixer fitted with the whisk attachment, add the flour, cocoa powder, sugar, baking powder, baking soda, kosher salt, and espresso powder. Whisk by hand until combined. Molly Bolton In a small bowl, whisk the buttermilk and sour cream together until smooth. Molly Bolton Add the buttermilk mixture, vegetable oil, eggs, and vanilla extract to the bowl of dry ingredients and mix on medium speed until just combined, about 30 seconds. Molly Bolton Pour the hot coffee into the batter. Gradually increase the mixer to medium speed and mix until a smooth, thin batter forms. Molly Bolton Bake the Cake: Pour the batter into the prepared pan. Molly Bolton Bake 30-35 minutes, until the top of the cake springs back when touched and a toothpick inserted in the center of the cake comes out clean. Set aside on a cooling rack while you prepare the ganache. Make the Chocolate Ganache: Place the chopped chocolate in a medium-sized, heatproof bowl; set aside. In a small saucepan, warm the heavy cream on medium just until the edges of the cream begin to bubble (do not let it boil). Pour the warm heavy cream over the chopped chocolate and leave undisturbed for 2 minutes. Whisk the chocolate and cream until a smooth ganache forms. Molly Bolton Add Ganache: Spread the warm ganache evenly over the warm cake. Molly Bolton Allow the ganache to set and the cake to cool completely, either at room temperature or in the refrigerator, before topping with frosting. Prepare Marshmallow Buttercream Frosting: When the cake is cooled and the ganache is set, prepare the marshmallow buttercream frosting. Using an electric mixer, beat the softened butter on medium speed until creamy. Add the powdered sugar and vanilla extract, and beat on medium speed until combined and creamy. Add the marshmallow crème and mix on medium speed just until combined. Molly Bolton Finish decorating Cake: Gently spread the frosting over the cake into an even layer. Molly Bolton Sprinkle with toasted graham cracker crumbs. Molly Bolton Rate It Print