Your primary problem is "beating until fluffy". You're incorporating air into the batter which makes it rise too much and crack apart during cooling.
Cheesecake is a form of custard. Meaning it is mesh of cooked denatured egg protein holding it together. With all that air expanding and lifting the batter, then cooling, it's too much movement for the egg protein to hold together.
Mixing cheesecake is about getting an even mixture with the least air in it. These are conflicting goals. What I've found successful is to mix until evenly incorporated, then stop. Now I tap the mixing bowl of batter on the counter top vigorously enough to bring air bubbles to the surface. Keep doing that until you don't see new bubbles coming up. Then pour into your chosen forms.
On an unrelated note, that seems like too much sugar. I use that much sugar for twice as much batter. Where these are small bites, i can see where a little extra sweetness might be appropriate, but I'd try a few batches with somewhat less sugar and see if you think the taste improves.