This past weekend was the beginning of the Mooncake Festival or the Mid-Autumn Festival, an important Chinese holiday. Chinese people usually celebrate by eating mooncakes and giving them to relatives. There are many different stories behind the festival, none of which I really remember hearing often and am familiar with only vaguely. Or maybe I just didn't listen. Serious Eats has a nice explanation of mooncakes and a review of a variety of them that you can get in Chinatown.
Mooncakes are a pastry with a slightly sweet, soft cookie exterior filled with a dense black or red bean paste and often with a dried egg yolk in the middle. We always had boxes of these in my house during the festival time when I was growing up, but mooncakes were never my favorite thing. And because they are so thick and rich, it's hard to eat a whole one at once. So it would take awhile to make that box disappear. And there are so many varieties, I never knew which we had gotten.
Serious Eats mentions one variety, "round and white cakes with a flaky exterior and red stamping on the surface" that is more prevalent in the Suzhou region. It was rare that we would get those, but those were always better - the black bean paste was tastier and the whole thing not quite as thick. If you're looking to try mooncakes, my recommendation would be to keep an eye out for that kind!