A snickerdoodle is an American sugar cookie rolled in cinnamon sugar before baking, giving it a crackled, faintly crisp surface over a soft, chewy interior. Its name's origin is unclear - one theory ties it to the German word "Schneckennudel" (a spiral pastry), but no version is confirmed.
The dough is a simple butter, sugar, egg, and flour mix, but what sets a snickerdoodle apart from a plain sugar cookie is cream of tartar paired with baking soda, which gives it a slightly tangy edge and a soft, dense chew. After shaping, the dough balls are rolled in cinnamon sugar rather than plain sugar before baking.
Snickerdoodles are a classic American cookie-jar and bake-sale staple, especially around the winter holidays, though they are eaten year-round. Common variations add vanilla or nutmeg, or swap in brown sugar for a chewier, more caramel-toned cookie.