Since icing on cookies will have to dry, prepare to make cookies one day in advance.

Bake cookies. Prepare cookie dough following recipe instructions. Using 4 in. round cookie cutter, cut out and bake cookies. Let cool.

Prepare royal icing. Prepare royal icing following recipe instructions. Using Black icing color, tint ¼ cup icing black. Using Royal Blue icing color, tint remaining royal icing blue. Thin blue icing to consistency of 10. Reserve blue icing for later step.

Prepare decorating bag with tip 3 and black royal icing; outline cookies. Let cookies dry 1 to 2 hours.

Decorate cookies. Using decorating brush, stripe cut decorating bag with Sky Blue icing color (for brighter blue accent) or Royal Blue icing color (for darker blue accent). Fill bag with reserved thinned blue icing. Fill in cookies. Using scribe tool, swirl icing. Let cookies dry 8 to 10 hours.

Using black FoodWriter marker, draw sharks on cookies.