Make the Chocolate Frosting: While the cakes cool, prepare the frosting. In a saucepan, melt the butter over medium heat. Add the cocoa powder and stir until smooth and fully incorporated.
Pour in the milk, vanilla extract, and salt, mixing until smooth. Gradually add the powdered sugar, stirring constantly, until the frosting is thick and spreadable. If you want a creamier frosting, you can add 1–2 tablespoons of extra milk to achieve your desired consistency.
Assemble the Cake: Once the cakes are completely cool, place one layer on a serving plate. Spread a generous amount of the chocolate frosting over the top. Then, place the second cake layer on top and frost the entire cake with the remaining frosting. Use a spatula to smooth the frosting evenly around the sides and top of the cake.
Decorate (Optional): For an extra touch, sprinkle chocolate chips, cocoa powder, or drizzle some extra chocolate sauce on top of the cake. You can also add some sprinkles or chopped nuts for texture and color.
