INGREDIENTS:
- Zip lock bags for piping
- 3 1/2 cups (1 pound) powdered sugar (plus more as needed)
- 1/2 cup liquid egg whites (4 large pasteurized egg whites)
- 1 teaspoon vanilla extract
- Food coloring of choice
- Water, as needed
DIRECTIONS:
- Sift powdered sugar through a fine-mesh strainer into a large bowl to remove lumps.
- Mix egg whites, vanilla, and sugar until the icing is completely smooth, glossy, and slightly thickened. The icing should hold a soft peak and slowly run off of the whisk attachment. If the icing is too loose, add more powdered sugar, 1/4 cup at a time, and continue mixing until completely incorporated.
- Separate some of the stiffer icing to use to outline shapes. With the remaining icing, add one teaspoon at a time of more egg whites or water to loosen it. Use the thinner icing to flood the cookies.
- When ready to decorate, add drops of food coloring to each zip lock bag and mix until color is uniform
- Decorate cookies with the icing and let completely dry before touching them, at least 4 hours