Stepwise Method

• Preheat your oven to 350°F (175°C) and grease your 8-inch round cake pans. Line the bottoms with parchment paper for easy removal.
• In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, Dutch-process cocoa powder, baking soda, baking powder, and salt until evenly combined.
• In another bowl, combine the eggs, buttermilk, hot black coffee, vegetable oil, and vanilla extract. Mix well until fully combined.
• Gradually pour the wet mixture into the dry ingredients. Stir gently until just combined, being careful not to overmix.
• Divide the batter evenly among the prepared cake pans. Bake for 25-30 minutes, or until a toothpick inserted into the center comes out clean. Allow the cakes to cool in the pans for 10 minutes, then transfer to a cooling rack to cool completely.
• In a medium bowl, beat the unsalted butter until creamy. Gradually add the powdered sugar and beat until smooth. Add the marshmallow fluff and mix until combined. Set aside.
• Using a kitchen torch, toast the marshmallows until they are golden brown. If you don't have a torch, broil them in the oven for a few minutes, watching closely to avoid burning.
• Once the cake layers are completely cooled, place one layer on a serving plate. Spread a layer of marshmallow filling on top, then add another cake layer. Repeat this process until all layers are stacked, finishing with a layer of filling on top.
• In a large mixing bowl, beat the unsalted butter until creamy. Gradually add the powdered sugar and Ovaltine, mixing until smooth. Add the melted chocolate, vanilla extract, and a pinch of salt, mixing until combined. Finally, add the heavy cream and beat until light and fluffy.
• Use a spatula to spread the malted chocolate frosting generously over the top and sides of the cake. You can create decorative swirls or smooth out the frosting for a sleek finish.
• Top the cake with any remaining toasted marshmallows for an extra special touch. Slice and serve to enjoy this decadent dessert!