Use coarser sugar for thicker, chewier cookies. When sugar dissolves, it acts as a tenderizer that interferes with dough structure. This increases spreading because finer sugar dissolves more easily than coarser sugar. So if you want your cookies to remain thick and chewy, use coarse sugar (or use fine sugar for the opposite effect). If you decide to use powdered sugar for extra crispiness, make sure it doesn’t have corn starch in it, or you’ll get unexpected results. [2] X Research source Mix these ingredients together until creamy.