Mix the powdered sugar, meringue powder, vanilla extract, almond extract, corn syrup, and water on high for 3 minutes to make a fluffy royal icing.
Use the royal icing to outline the cookies, creating a border or small details like Christmas tree branches.
Thin out some of the royal icing with a spray bottle to get a flood consistency, which is good for filling in the cookies.
Repeat the process for every color of icing you need.
