Prepare imprinted top. Roll out 24 oz. white fondant 1/8 in. thick. Cut an 11 x 17 in. rectangle; imprint Happy Birthday design using Imprint Mat. Use shell tool from set to fray edges.
Brush cake top with water and position imprinted top. Use tip 1 to outline and fill in designs using icing in assorted colors. Attach letters with dots of icing. Pipe tip 5 bead bottom border.
* Combine Lemon Yellow with Golden Yellow for yellow shown.
* Combine Leaf Green with Lemon Yellow for green shown.
* Combine Violet with Rose for violet shown.