Hi, so I recently made my very first ever cheesecake. It was going fine until after I got it out of the oven. It was puffed up and looked perfect when I got it out, the middle seemed set like the instructions said. However, after it had been out of the oven for awhile, it deflated and sunk in the middle. It still tasted great and I didn't receive any complaints about it. But still, I'd really like to know how to tell if it's really done so that it won't sink in the middle in the future.