Here is the scenario:
You are craving a batch of cookies.
You pull out a recipe and start putting things together -- everything is going well and the batter looks great. They go in the oven and puff up and suddenly begin to spread out. Before you know it you have a sheet full of cookies as flat as pancakes. Like these:
Now, they still taste ok, but the texture is off. Sometimes they are too crunchy. And it can be frustrating. What went wrong?
Here are some strategies to help prevent this from happening:
1. When you cream your butter, be careful not to heat it too much. It should be pliable, but not weepy.
2. Chill your dough, and keep the batter in the fridge between batches. Some people even freeze their chocolate chips to help keep the cookie in better shape.
3. Mound your dough higher when putting it on your baking sheet
4. You could be over-mixing. It adds air, which causes them to puff up and deflate (like a souffle). It also causes the butter to melt more. So go easy on it.
5. Check the expiration date on your baking powder and baking soda. Also, baking soda can tend to make cookies flat, so try reducing that a little.
6. Use medium or large eggs (not extra large). Too much egg will flatten a cookie. If you are only making 1/2 a batch of cookies and there is an uneven number of eggs, use the egg yolk instead of a whole egg.
7. Try swapping 1/2 of the butter for shortening or crisco. Cookies using all butter will flatten out a bit more.
Baking is a science, with many factors to think about. Good Luck!