Heat oven to 350°F (325°F for dark or nonstick pans). Spray or grease bottoms only of two 9-inch round cake pans. Make cake batter as directed on box.
Divide cake batter evenly among 3 separate bowls (about 1 cup for each bowl). Dye each bowl a different color with pink, purple or yellow food color. Pour half of the purple batter into each of the 9-inch round pans. Pour half of the yellow batter over top of the purple layer in each pan. Pour half of pink batter over yellow batter in each pan. Do not mix.
Bake and cool cake as directed on box for two 9-inch rounds. Cool 10 minutes. Remove from pans to cooling racks. Cool completely, about 1 hour.
Place one of the cooled cake rounds on serving tray. Cut other round cake as shown in Diagram A below and place ears and bow tie of the bunny in appropriate places on the tray.
Carefully frost cake with frosting. Sprinkle coconut over cake. Use licorice to outline bow tie and make whiskers and mouth on bunny. Use jelly beans for eyes, nose, and to fill in bow tie. Use pink sprinkles to fill in pink of the ears. Store covered at room temperature.