This is the ideal icing for rolled sugar cookies. It can be tinted with food coloring. Mix up a thick batch for piping out of zip-top bags (cut off one bottom corner) or piping bags.

Stir together in a medium bowl until smooth:

If necessary, adjust the consistency with more:

Color as desired. To store, cover the surface of the icing with plastic wrap. This keeps for up to 4 days at room temperature or for about 1 month refrigerated.