Preparation:

Step 1: Preheat the Oven & Prepare the Cake Pans

Preheat your oven to 350°F (175°C). Grease and line three 8-inch cake pans with parchment paper, making sure to coat the sides with butter or non-stick spray for easy removal after baking.

Step 2: Make the Graham Cracker Crust

In a mixing bowl, combine graham cracker crumbs, granulated sugar, and melted butter. Stir well until the crumbs are fully coated. Divide the mixture evenly among the three cake pans and press it firmly into the bottom to create an even crust. Set aside.

Step 3: Prepare the Chocolate Cake Batter

In a large mixing bowl, whisk together the all-purpose flour, sugar, cocoa powder, baking powder, baking soda, and salt. Add in the milk, vegetable oil, eggs, and vanilla extract. Using an electric mixer or whisk, beat the mixture until smooth and fully combined. Once the batter is well-mixed, carefully stir in the boiling water. The batter will be thin, but that’s okay—it ensures a moist cake.

Step 4: Bake the Cake

Pour the cake batter over the graham cracker crusts in the prepared pans. Bake for 30 to 35 minutes, or until a toothpick inserted into the center of the cake comes out clean. Allow the cakes to cool completely in the pans, then gently turn them out onto a wire rack to finish cooling.

Step 5: Make the Marshmallow Filling

In a large mixing bowl, beat together the marshmallow fluff, softened butter, powdered sugar, and heavy cream using an electric mixer. Beat on medium-high speed for about 3-5 minutes, or until the mixture becomes smooth, fluffy, and light. Set aside for assembly.

Step 6: Prepare the Chocolate Ganache

In a small saucepan, heat the heavy cream over medium heat until it begins to simmer. Pour the hot cream over the dark chocolate chips in a heatproof bowl. Stir gently until the chocolate has completely melted and the ganache is smooth. Let it cool slightly at room temperature to thicken up before using it on the cake.

Step 7: Assemble the Cake

Place one layer of chocolate cake on a serving plate. Spread a generous amount of marshmallow filling evenly over the cake layer. Place the second cake layer on top and repeat with another layer of marshmallow filling. Top with the final cake layer. Pour the cooled chocolate ganache over the top of the cake, allowing it to drip down the sides for that signature “s’mores” look.

Step 8: Garnish and Serve

To finish off the cake, top with mini marshmallows that have been lightly toasted using a kitchen torch. Sprinkle the cake with crushed graham crackers and chocolate chunks for extra texture and flavor. Slice and serve, making sure to enjoy every gooey, delicious bite.