Make mini cakes. Prepare batter following recipe directions. Bake and cool mini cakes according to pan package directions.
Cover mini cakes in icing. Tint portions of icing violet, rose, blue, orange and green; reserve the remaining white in can. Heat white icing in microwave at defrost setting (30% power) for 20-30 seconds; stir. Repeat until consistency of icing will pour. Place mini cakes on cooling grid positioned over parchment paper-lined cookie sheet. Pour icing over cakes; tap grid gently to settle. Let set 1 hour.
Decorate mini cakes. Use tip 3 and rose icing to pipe mouth and nose. Use tip 3 and blue icing to pipe dot eyes. Use tip 2 and violet icing to pipe whiskers.
For ears, use tip 2 and orange icing to outline inner ear. Use tip 3 and rose icing to fill in middle ear. Pat smooth with finger dipped in cornstarch. Use tip 2 and green icing to pipe dots.