Make your cakes according to directions and let cool. I also recommend refrigerating them to make icing them a little easier. Trim off sides to make a rounded top, gently placing on the other 2 layers. Ice between layers and then do a crumb coating on the top.
Sort your Reese's Pieces by color. You will need the black and orange ones. Gently cover the cake in a basketball pattern and let the frosting set.