01 -
Preheat the oven to 175°C. Grease two 23 cm round cake pans and line the bottoms with parchment paper. In a large bowl, whisk together the flour, sugar, cocoa powder, baking soda, baking powder, and salt. In a separate bowl, combine eggs, buttermilk, and vegetable oil until smooth. Add the wet ingredients to the dry and mix until thick and consistent. Gradually whisk in the hot coffee or water until the batter is thin and silky. Divide evenly into prepared pans and bake for 25 to 30 minutes or until a toothpick inserted in the center comes out clean. Let cool 10 minutes in pans, then transfer to wire racks to cool completely.
02 -
Beat the softened butter and sugar together in a large bowl until light and fluffy, about 3 to 4 minutes. Incorporate the marshmallow creme and mix until fully combined. In a separate chilled bowl, whip the heavy cream until stiff peaks form. Gently fold the whipped cream into the marshmallow mixture until smooth and airy. Refrigerate until ready to assemble.
03 -
Place one cooled cake layer onto a serving platter. Spread the cream filling evenly to the edges. Top with the second cake layer and gently press down. Refrigerate the assembled cake for 20 to 30 minutes to set the filling and prevent sliding during ganache application.
04 -
Warm the heavy cream in a saucepan until it just begins to simmer. Pour over the chocolate chips and let sit for 2 minutes to melt. Stir gently until smooth, then add the butter and mix until the ganache is glossy. Cool for 5 minutes, then pour evenly over the chilled cake, allowing it to drip naturally over the edges. Refrigerate until set.