The Cookie That Smells Like a Hug There is something about the cinnamon-sugar crackle on a snickerdoodle that makes everything feel right in the world. These are soft, chewy, and slightly tangy from the cream of tartar -- which is the ingredient that makes a snickerdoodle a snickerdoodle and not just a sugar cookie in disguise. The Signature Crackle Cream together the butter and sugar until light and fluffy, then beat in the eggs and vanilla. In a separate bowl, whisk the flour, cream of ta