1Heat oven to 375°F. In large bowl, stir cookie mix, butter and egg until dough forms. On lightly floured surface, roll dough to 1/4-inch thickness. Cut with 3-inch round cookie cutter. On ungreased cookie sheets, place cutouts about 2 inches apart. Insert 1 craft stick halfway into center of each cookie.
2Bake 9 to 11 minutes or until edges are golden brown. Cool 2 minutes; remove from cookie sheets to cooling racks. Cool completely.
3In small bowl, mix 1 cup of the vanilla frosting and the blue food color. Frost cookies. Let stand 10 minutes. With decorating icings, pipe thick stripes of each color for rainbow. Spoon remaining vanilla frosting into decorating bag fitted with 1/2-inch round tip. Pipe clouds on cookies. Let stand until set.