A cookie's chewiness or crispiness depends a lot on the ratio of ingredients in it. For instance, if you wanted a chocolate chip cookie with more spread, which will also tend to be on the crispier side, look for a recipe that uses mostly granulated (white) sugar. Brown sugar, on the other hand, contains more liquid in it, which is key in making a more moist and chewy cookie. However, these aren't hard and fast rules for *every* cookie recipe because the role of sugar changes a bit with the ingredients around it. You can read more about each kind of sugar in this fascinating article from Serious Eats.