Each mini cake serves 1.
Bake your favorite cake recipe or mix in pan, baking about 1/3 cup batter in each heart cavity. Cool in pan on wire rack 10 minutes. Remove from pan and cool completely. Position cakes on same size cake boards. Lightly ice in buttercream icing to prepare for fondant covering.
Roll out green, pink and yellow fondant 1/8-in. thick. Cover cakes with fondant; trim, reserving excess fondant.
For green cakes, roll out 3 contrasting colors of fondant; cut a different size heart from each color using Cut-Outs. Center and layer hearts attaching with damp brush. Using remaining green fondant, roll about 32 1/8-in. balls. Attach to heart with damp brush.
For pink cake, roll out white fondant and cut 1/4-in. wide strips. Arrange strips, criss-crossing diagonally; attach with damp brush.
For yellow cake, roll out white fondant and cut flowers using smallest Cut-Out. Attach to heart with damp brush. Roll small balls of orange fondant for flower centers; attach with damp brush.