In advance: Prepare foamcore base board. Use Elmo pan and hat pattern as guides for top portion; bottom will be a 10 x 17 in. rectangle. Cut then wrap with foil.
Also: Make cookies. Prepare and roll out cookie dough. Use Push 'N Print Set to cut 7 "Happy Birthday" cookies. Use patterns to cut 2 hands. Bake and cool cookies; decorate with royal icing. Place hand cookies on waxed paper-covered board; cover top and sides with tip 16 stars. For "Happy Birthday" cookies, use tip 2 to fill in letters and outline edges (leave 3 undecorated).
Bake and cool cupcakes. Ice smooth with buttercream. Use tip 3 to add scalloped border. Position icing decoration in center.
Bake and cool Elmo cake and 1-layer 11 x 15 in. sheet cake. Pipe in mouth, nose, eyes and pupils with tip 3 (smooth with finger dipped in cornstarch); add tip 3 smile lines. Cover face with tip 16 stars. Position cake on prepared board.
Roll 3/4 in. diameter fondant balls for bottom border on sheet cake; attach with dots of icing. Pipe a tip 3 spiral in buttercream icing on each ball.
Roll out a small amount of fondant 1/4 in. thick; use pattern to cut hat base. Position against top of Elmo's head. Roll out a portion of fondant 1/2 in. thick; use pattern to cut hat top. Shape and position on board.
Prepare Elmo's decorating bag with icing, tip and coupler; twist top closed and secure with a rubber band. Position bag, hands and cookies; attach to cake top with icing.
The star tip creates the most celebrated, easily accomplished decorations! The serrated edges of the star tip make ridges in the icing as you squeeze it out. Because fill in requires so much piping from the same bag, keep replenishing icing in bag.