Originally Posted by karess
In fact, I just learned in school that cookie dough is better to be made at least 24 hours ahead of time before baking because then all of the flavors can develop together.
I once worked with a chef who absolutely REFUSED to bake cookie doughs that were made the day of. Even with fresh cookie dough that had been sitting in the fridge for two hours, he'd tell the front of the house that we were out of cookies.
karess is right, don't cream your sugar and butter too much. I stop when I no longer see any butter. Using butter that's at room temperature helps. Over-mixing goes for all the steps of making the cookie as well. Don't wait around until all your eggs are completely, 100% incorporated. Just go ahead and add the flour. Obviously you DO want everything incorporated, but don't overmix or your cookie will flatten. Use a spatula to scrape the bottom of your bowl often to help the process along. When I add the chocolate chips I only leave the mixer on for a second or two. You don't want to break them and you don't want to over-mix, either.
Then I take my batter out of the bowl and evenly incorporate the chocolate chips by hand (threre's always that ball of batter that gets wrapped around the paddle and doesn't get any chocolate chip cookies).
Roll your dough into little balls and refrigerate (scoop or weigh each one so they're all the same size and bake at the same time). Take them out of the fridge and bake them when they're cold. I find that greasing the bottom of my sheet tray tends to make the cookies spread too much, too, so I use parchment paper instead. Stack two sheet trays together if you can, to avoid overcooked bottoms.
Good luck! Chocolate chip cookies were the first thing we baked in culinary school. When our chef told us that we'd be working on chocolate chip cookies we all snickered. "I got this. I've been making chocolate chip cookies since I was a kid. This is a waste of time," people kept saying. Some guy even said that only an idiot could mess up chocolate chip cookies.
Guess what? We ALL failed. In fact, our very first practical weeks later was on chocolate chip cookies (among other things) and several of us would come to school on Saturday mornings so we could practice making them. Some people even failed the practical because they didn't practice enough and their cookies flattened.
Chocolate chip cookies, man. Chocolate chip cookies and biscuits. OMG, you'd think they'd both be so easy. Big fat NO.