Step 3 — Make the Chocolate Frosting
In a saucepan over medium heat, melt the butter. Add the cocoa powder, confectioner's sugar, and milk. Stir constantly until well combined and the mixture reaches a smooth, hot fudge-like consistency. Remove from heat and stir in the vanilla extract. Immediately pour the warm chocolate frosting over the coconut-filled cake, spreading it evenly to cover every inch. Work quickly, as the frosting will begin to set as it cools.
Step 4 — Chill and Serve
For the best results, refrigerate the cake overnight. This allows all the flavors to meld together beautifully and gives the frosting that perfect fudgy texture. When you're ready to serve, slice and enjoy cold or at room temperature.
