Make Shape-N-Amaze 3-D character three days in advance. Use online directions to create bunny cake topper.
Create eggs. Tint 1 oz. of white fondant each yellow, blue, rose, orange and violet. Use 9 in. fondant roller with pink guide rings to roll out each 1/16 in. Use egg cutter from set to cut four of each color. Let dry on cornstarch-dusted surface 3 to 4 hours.
Make cake. Prepare batter following recipe directions. Bake and cool 3-layer cake according to pan package directions. Place on a foil-wrapped cake circle.
Cover cake with fondant. Prepare buttercream icing following recipe directions. Use spatula and icing to lightly ice cake. Tint 14 oz. of white fondant green. Use fondant roller with orange guide rings to roll out 1/8 in. thick. Cover cake with fondant.
Decorate cake. Tint 2 oz. of white fondant a slightly darker shade of green. Use fondant roller with blue guide rings to roll out 1/16 in. Use knife to cut two bands, 20 in. x 1 1/4 in. Use knife to cut out triangles on band to make blades of grass. Use damp brush to attach grass bands around base of cake.
Use damp brush to attach eggs between two layers of grass bands and directly on cake behind bands.
Position cake topper.