Prepare buttercream icing, divide and tint portions red and yellow, reserve white. Assemble cake layers on foil-wrapped cake board, spreading thin layer of buttercream icing between layers. Spatula ice cake smooth. Imprint medium star cutter on cake sides. Using tip 3 and yellow icing, outline stars. Using tip 16 fill in with stars. Using tip 6 and red icing, pipe top and bottom bead borders. Position cookie on cake top, securing with a swirl of buttercream icing.
*Combine Lemon Yellow and Golden Yellow Icing Colors for yellow shown