Prepare cake batter according to recipe. Bake for 30 minutes, or until a toothpick inserted in the center of each cake comes out clean.
Let the cakes cool in pans on a wire rack for 30 minutes before inverting onto the wire racks to cool completely while you prepare frosting.
Prepare frosting and then level the top of each cake layer, if needed, and slice each cake layer in half horizontally. You should have 4 cake layers.
Spread frosting between each cake layer until all 4 have been stacked. Spread the remaining frosting on the top and sides of all the layers.
Using a vegetable peeler, scrape the blade lengthwise across the room-temperature block of dark chocolate to create curls. Garnish the top rim and side of the cake with the chocolate curls.
Use the white decorating icing to create the countdown clock.