Using cream of tartar is the key to getting the signature snickerdoodle taste. Cream of tartar not only gives snickerdoodles their flavor but also helps them get that characteristic crackly top when baking. Cream of tartar is a common baking ingredient that often gets overlooked. While it may seem strange, this ingredient actually serves a very important purpose in your favorite holiday cookies! Cream of tartar works as an acidic agent to help the cookie dough rise. In addition to being used in snickerdoodles, you can also find the cream of tartar in other recipes, including cakes, frostings, meringue, and even some jam.