Easy Royal Icing gives your sugar cookies the royal treatment; the results are always pretty and polished. This tried-and-true recipe goes on like silk, dries firm, and tastes fantastic.
In a standing mixer fit with the whisk attachment on medium-high speed, add the egg whites and vanilla and beat until foamy.
Reduce mixer speed to low and add the powdered sugar until just incorporated and shiny. Beat on high for 5 to 7 minutes or until the mixture is thick and glossy with stiff peaks.
Add food coloring if desired, then transfer to piping bags or spread with a spatula. If using sprinkles or sugar, add quickly before the frosting hardens.
To make in advance, store in an airtight container in the refrigerator for up to 3 days.