THE FIX: The texture of cookies—cakey, crispy, chewy—depends partially on the fat and the number of eggs used in the dough. Fat plays a major role in how much a cookie spreads. In general, more fat yields flat, crispy cookies as the butter melts, causing the dough to spread, while less fat means less spreading and puffier, cakelike cookies. Many cookie recipes use a combination of oil and butter, which creates a soft and tender cookie without excess spreading because the oil disperses throughout the dough. The fat and protein in egg yolks bind the dough, give it richness, and create a crisp cookie, while egg whites have a drying effect that makes cookies cakey. Another cause of cakey cookies: Too much flour. Even an extra tablespoon or two can be too much for a cookie dough, so be sure you’re measuring accurately.