Using a sharp knife, cut the cake layers according to the diagram.
To make the frosting: heat the milk until hot but not boiling. Combine sugar, butter, 1 tablespoon of the milk, and vanilla extract in the large bowl of a beater, and beat on high until well combined. The frosting should be thick and spreadable but not stiff. Add more hot milk, a little bit at a time, until the frosting is a little softer than smooth peanut butter. If it is too runny, add more confectionery sugar.
Liberally frost the cake, and lavishly decorate with coconut all over. Then arrange the bunny cake on the platter. You can give your bunny a spring look by mixing 1-2 drops of the food color of your choice in a little water along with some of the coconut in a glass jar. Cap tightly and shake the jar to coat the coconut. Decorate your bunny cake using gumdrops or chocolate chips for eyes and nose, and thin Twizzler strips for whiskers. You can also pipe colored frosting.