What causes chocolate chip cookies to flatten while baking?

Why oh why oh WHY did my beautiful sheet of chocolate chip cookies turn into a big, ugly blob as they baked? Well, there are several reasons cookies spread. A touch too much sugar, for one – sugar is hygroscopic; it absorbs liquid. read more

Chocolate chip cookies that have a high butter content and too much liquid tend to spread as they bake. Adjusting your recipe's liquid and the ingredients that absorb it changes the texture and shape of your cookies. read more

The primary difference between these two trays [photos below] is the baking temperature. One reason cookies spread: oven temperature “The failed tray baked at 350°F for 14 minutes. “For this practically perfect tray, we dropped the temperature to 300°F, and extended the baking time: 22 minutes for chewy, 30 minutes for crisp. read more

Leavening like baking powder or baking soda- High amount of leavening will cause the cookie to collapse when baking producing a flat cookie. Adjusting the quantity of ingredients will affect the look, texture and dimensions of the cookies. read more