4 egg whites
4 cups confectioners sugar
Water (for flooding)
food coloring
Sift powdered sugar.
Whisk egg whites until they just begin to foam, then incorporate powdered sugar a little at a time. *See notes about water.
Put a few spoonfuls into a ziplock bag, snip off just a small corner, and pipe onto cookies.
When the icing is dry on the surface, put the cookies in a single layer and cover. Allow to dry overnight before stacking.
Tightly sealed up, your icing will be good to use for a day or two.
*For the best results, make the icing with no water or only the amount of water you need to make thick icing. Draw on your outline. Let dry.
Mix a tiny amount of water at a time into the icing until you reach the consistency needed for flooding. Fill in the center of the area you drew, then use a toothpick to push it out to the edges.