This is truly the easiest and the most perfect sugar cookie icing recipe! The icing is delicious, it does not overpower the flavor of the cookies, hardens without becoming too crunchy, and it's great for decorating too.
In a medium bowl, combine powdered sugar with corn syrup, and the extract of choice. Use a whisk or a spoon to mix.
Add milk about 1 teaspoon at a time until you reach the desired consistency.
Divide into bowls (depending on how many colors you want to make), and add food coloring to each.
To Ice Cookies (2 Ways):
Dip one side of the cookies right in the icing in the bowl, shake off any excess and transfer to a wire rack to set. If using sprinkles, decorate right away before the icing sets.
Or make 2 different consistencies for the icing, a thicker one for outlining the cookies and a thinner one for flooding the cookies. Add to pipping bags, then outline the cookie and wait for 10 minutes so the outline sets. Then flood the inner section of the cookie with a thinner consistency. Decorate with sprinkles if using, then transfer to a wire rack until the icing sets completely.
Notes
Details: Keep in mind that with this cookie icing you won't be able to create a lot of detail as you would have if you were using Royal Icing.
Instead of a piping bag, you can add the flood-consistency icing to your cookies using a squeeze bottle, or you can add a dollop of icing and spread it out using a small spatula, spoon, or brush.
Consistency: I make my icing for outlining the cookie to have a similar consistency to peanut butter, and for flooding the cookies it should be similar to heavy cream.