Preheat the oven to 350 degrees F.
Spray 5 (4 by 2-inch) high cake pans with nonstick cooking spray. In a large mixing bowl, combine the cake mix, eggs, oil, and chocolate milk. Beat on medium speed for 2 minutes, scraping down the bowl to be sure the batter is well incorporated. Fill each pan two-thirds of the way to the top. Bake in the oven for 12 to 15 minutes, rotating the pans halfway through baking. A toothpick inserted in the center should come out clean when done. Remove from the oven. When the pans are cool enough to handle, unmold the cakes and cool completely, right side up on a wire cooling rack.
In a large bowl, mix together the milk chocolate frosting with cocoa powder.
To decorate: Using a serrated knife, level the tops of each cake (crumble the extra cake for cake crumbs to decorate). Adhere each cake to a 4-inch cardboard cake board using a dab of frosting. Ice the top and sides of the cake using an offset spatula. Using a different ingredient for each, cover the sides of each cake by holding over a bowl and using hands to gently press the nuts, coconut, etc. into the sides of each cake. Place each onto small silver cake pedestals of varying heights. Top each with 2 or 3 chocolates and truffles.