Makes 2 cups icing or enough to assemble and decorate one Gingerbread House or School/Post/Office.
Place all ingredients in a medium, non-plastic mixing bowl. Beat at medium speed of electric mixer 5-7 minutes or until icing is glossy and holds peaks. The icing dries very quickly; cover with a damp towel when not being used. To store for later use, place in an air-tight container and refrigerate. Mix thoroughly before using. Icing may be tinted using food coloring (liquid, paste, or powder), if desired. *3 tbsp meringue powder can be substituted for egg whites. Add to the powdered sugar along with 6 tbsp warm water. Omit cream of tartar.