Cookies spread because the fat in the cookie dough melts in the oven. If there isn't enough flour to hold that melted fat, the cookies will over-spread. Spoon and level that flour or, better yet, weigh your flour. If your cookies are still spreading, add an extra 2 Tablespoons of flour to the cookie dough.

Why do my cookies flatten out?

Mistake: When cookies turn out flat, the bad guy is often butter that is too soft or even melted. This makes cookies spread. The other culprit is too little flour—don't hold back and make sure you master measuring. ... If too-little flour was the issue, try adding an additional 1 to 2 tablespoons of flour to the dough.

What contributes to the spread of a cookie?

Excess Sugar and Fat

Measuring is key in baking. If your cookie contains excess sugar or fat, it will spread while baking. If your first batch of cookies spreads, try adding a few tablespoons of flour to help thicken the remaining dough.