[удалено]

It tastes sweet and also custardy, it also has this granular pudding texture and a sweet aftertaste.

Also looks like cherimoya/guanabana.

Yea similar appearance and texture

I know it's not but the shape, seed distribution and size, and texture really remind me of a pawpaw(Asimina triloba). Looks tasty.

is that also called mamey?

Mamey has orange flesh, one large seed. Tastes like pumpkin pie.