Prepare 3 boxes white cake mix following package instructions; divide in thirds. In one portion of batter, gently stir in Violet Icing Color to desired shade (use clean toothpicks to transfer color from jar to batter). Repeat with Golden Yellow Icing Color to color second portion. Repeat with Rose Icing Color to color second portion.
Place Batter Dividing Ring in the first prepared 9 x 1 1/2 in. pan. Pour violet-colored batter in outer section and yellow-colored batter in the middle section and rose in center section. Fill sections halfway. Remove ring from pan by carefully lifting straight up on handles. Rinse and completely dry ring.
Place ring in 2nd prepared pan and in the first prepared 9 x 1 1/2 in. pan. Pour yellow colored batter in outer section and rose-colored batter in the middle section and violet colored batter in center section. Fill sections halfway. Remove ring from pan by carefully lifting straight up on handles. Rinse and completely dry ring.
Place clean and dry ring in 3rd prepared pan. Pour rose-colored batter in outer and violet-colored batter in the middle section and yellow-colored batter in the center section. Fill sections halfway. Remove ring from pan as before.
Bake and cool cakes following recipe directions. Remove and stack cakes with buttercream. Ice smooth.
Using the bunny cutter from the 3-Pc. Easter Cutter Set, mark the cake sides. With tip 3 and white buttercream icing, outline the bunnies and inside of the ears.
Using tip 3 and rose buttercream icing, fill in inner ears. Pat smooth with finger dipped in cornstarch. Dot nose.
With black buttercream icing and tip 3, pipe dot eyes and outline mouth.
Cover the bunny heads by piping stars using tip 14 and buttercream icing. For bottom border, pipe green buttercream tip 233 pull-out grass. Pipe a 6 in. diameter circle on top of the cake using tip 233 pull-out grass with green buttercream icing. Position jelly beans in grass at bottom border and on top of cake.
The star tip creates the most celebrated, easily accomplished decorations! The serrated edges of the star tip make ridges in the icing as you squeeze it out. Because fill in requires so much piping from the same bag, keep replenishing icing in bag.