Step 1

Place the egg whites in the bowl of an electric mixer fitted with the whisk attachment or beaters. Beat on medium speed until frothy.

Step 2

Add the confectioners’ sugar and beat on low speed until blended. Increase the speed to medium-low and beat until the mixture is thick and shiny, 3 to 5 minutes. Divide the icing into bowls depending on how many colors you plan to use. Use food coloring to tint the icing and then add water, little by little, to get the right consistency. Use a thicker icing for details and outlines and a thinner icing for "flooding," or fully covering the surface of the cookies. Place a damp paper towel directly on top of the icing to keep a skin from forming on top. If not using within 2 hours, cover the bowls tightly with plastic wrap and refrigerate. (Icing may also be kept in airtight squeeze bottles.)

Step 3

Note: If you're concerned about using raw eggs, feel free to use meringue powder, which can be found in the baking aisle of most large supermarkets or craft stores. Reconstitute the powdered egg whites according to the package instructions, making sure the powder is completely dissolved, and proceed with the recipe.