Sugar Cookie Icing: Velvety Frosting That Dries Hard

Instructions:

1. In a large mixing bowl, combine the sifted powdered sugar, salt, and 3 tablespoons of milk. Stir with a spatula until the mixture forms a thick, lumpy paste.
2. Add the corn syrup and vanilla extract, whisking until the icing becomes smooth and takes on a glossy sheen.
3. Test the consistency by lifting your spatula; the icing ribbon should disappear back into the surface in exactly 15 seconds. Adjust with small amounts of milk or powdered sugar if necessary.
4. Divide the icing into smaller bowls and add gel food coloring as desired.
5. Transfer icing to piping bags. Outline the edge of cooled sugar cookies first, then immediately flood the center. Use a toothpick to pop air bubbles.
6. Allow cookies to dry undisturbed for up to 24 hours until the icing has hardened completely for stacking.