Heat oven to 350°F. Grease and flour two 10-oz. custard cups, two 8-inch round cake pans and one 9-inch round cake pan. In very large bowl, combine cake mixes, water, oil and eggs; beat at low speed until moistened. Beat 2 minutes at medium speed. Spoon 3/4 cup batter into each greased and floured custard cup. Divide remaining batter evenly into greased and floured cake pans. Place cake pans in oven first, then custard cups.
Bake at 350°F. Bake cakes in custard cups for 25 to 30 minutes; bake cakes in round cake pans for 40 to 45 minutes or until toothpick inserted in centers comes out clean. Cool 15 minutes. Remove cakes from cups and pans; place on wire racks. Cool 45 minutes or until completely cooled.
With serrated knife, trim tops of all cakes to level. Place one 8-inch round cake on serving plate, trimmed side up. Spread small amount of chocolate frosting on cut surface of cake. Top with remaining 8-inch round cake, trimmed side down. Frost sides and top of cake with chocolate frosting.
Place 9-inch round cake, trimmed side down, on top of 8-inch layer cake to form brim of hat. Frost with chocolate frosting.
Spread small amount of vanilla frosting on cut surface of each trimmed custard-cup cake. Place frosted surfaces of cakes together to form ball. Place ball on top of 9-inch round cake for head of bunny. Insert bamboo skewers through head and hat to secure; about 2 inches of skewers will stick out of top. Insert cookies onto skewers for ears. Frost bunny head and ears with vanilla frosting.
Cut large marshmallow in half for paws; place on cake in front of "head." Cut miniature marshmallow in half for eyes; flatten slightly and place on "head." With small amount of frosting, attach blue candies to marshmallow "eyes." Use licorice for whiskers. Cut fruit roll into pieces for nose, inside of ears and bow.