Learn the easiest method to make Sugar Cookie Icing for decorating cookies for every day and holidays. It hardens on the cookies, takes minutes, and doesn't require any fussy ingredients.
Add the powdered sugar to a small bowl. Add 1 teaspoon of milk and stir to make a thick but spreadable icing. If the icing is still too thick, add the second teaspoon of milk. (You want it to be able to spread easily on the cookies and not be too thick. If you place some on the cookies and it runs right off, add a little more powdered sugar. If it's too thick to spread, add a drop or 2 of milk.)
You can color the icing with a drop of food coloring if desired.
Use a small butter knife or paintbrush to spread on the icing or pipe on as desired. If adding sprinkles or other decorations, add them to the iced cookies right away before it dries.
Notes
Store prepared cookies in an airtight container at room temperature for 3-5 days.
Know that a very small amount of milk goes a long way when mixed with powdered sugar so do your best to follow the recipe even if you think there should be more milk.
Dairy-free: Use your favorite nondairy milk.
Feel free to add 1/4 teaspoon vanilla extract if desired.