Make 4 cups buttercream icing:
Tint 1/2 cup black
Reserve 3 1/2 cups white

Make 1/4 cup white royal icing

Use 1 1/4 cups of piping gel:
Tint 1/4 cup yellow
Tint 1/4 cup blue
Tint 1/4 cup pink
Tint 1/4 cup green
Tint 1/4 cup violet

In Advance: Bake and cool cookie using Roll-Out Cookie recipe and largest circle cutter in 101 Cookie Cutter Set. Ice cookie smooth in white royal icing. Let set.

Decorate in Order:
1. Ice cake smooth in white buttercream icing.
2. Using black buttercream icing, pipe tip 3 outlines for stained glass on cake and cookie.
3. Using yellow, pink, violet, blue and green piping gels in cut parchment bags, fill in stained glass areas.
4. Using white buttercream icing, pipe tip 3 bead border on top edge of cake.
5. Using white buttercream icing, pipe tip 21 shell bottom border.
6. Position cookie on cake top.