Puffed chocolate chip cookies

Yes, I made cookies, I don't really like baking cookies, but I made cookies. Don't get me wrong, I like eating cookies, I just find that my cookies never turn out the way I wanted them to turn out. These cookies were made with a recipe my coworker gave me. She made it for work one day and it was soft and chewy, just the way I like it. I asked her for her secret and I told her about my many failing attempts of baking soft chewy chocolate chip cookies. She gave me this recipe and said, "take this, this is fool proof". Well, she was wrong, it's not fool proof. It was a great recipe, the cookies were delicious, but mine did not turn out soft or chewy. Instead, mine turned out cakey. Not that I didn't enjoy these, they just didn't turn out the way I wanted. I'm still searching for "the trick" in baking chewy cookies...please share with me your words of wisdom. 

Happy baking!