Make an easy icing for sugar cookies using powdered sugar, powdered egg whites and your choice of gel food colors.This recipe goes with Decorated Sugar Cookies
Beat powdered sugar and Just Whites in a large bowl with mixer on low speed until combined. Add 1/3 cup water; beat until blended. Increase speed to high; continue to beat 8 minutes or until icing is very thick. Icing can be tinted with paste or gel food colors, as desired. Pipe onto cookies, or thin with a bit more water for spreading.
To pipe icing: Use a pastry bag fitted with a plain tip, or fill a zip-top plastic bag with icing and snip off 1 of the corners. Pipe icing along the edges of the cookies or in a pattern you like. Immediately sprinkle with decorating sugar or edible glitter, if desired.