This is the only icing I use. I love that all the ingredients are pantry staples and easily bought at any grocery store (with the exception of the white food color, which is an optional ingredient). This icing will dry firm to the touch, but remain soft underneath. It does not get hard or crunchy. Iced cookies can be bagged and stacked approximately 12-18 hours after decorating.
*3 cups powdered sugar, sifted
*3 tablespoons corn syrup
*3 tablespoons water or milk
*3/4 to 1 teaspoon extract
*15 drops brite white food color,optional (I use Americolor)
In a medium bowl and with a spoon, mix together the first four ingredients until fully blended. Add the brite white and mix. The icing should have the consistency of honey, or white school glue. If you need to thicken, add more powdered sugar in small amounts. If you need to thin, add more corn syrup in small amounts. Divide and color.
This icing does not like to get cold. Refrigerating decorated cookies is not recommended, but if you must, wait a full 24 hours before doing so. While there will be nothing wrong with the icing, it will look splotchy. (The brite white will help with this problem, but is not a full fix). The leftover icing CAN be refrigerated, and will remain fresh for 10-14 days. Even when using milk, you don't have to worry about the decorated cookies spoiling. The high sugar content acts as a preservative.
Need more or less icing? Keep the proportions the same: 1 tablespoon corn syrup and 1 tablespoon liquid to every cup of powdered sugar.