Deconstructed Pizza Casserole

Not quite sure why it's called "Deconstructed" Pizza casserole. I have been kind of looking for a Pizza Casserole since I started doing the Keto Diet, I have been turned off by a lot of them because they all have cauliflower in them. I don't have anything against cauliflower. I just haven't gotten the guts to try it. I really should have bought a smaller pan to cook this in I don't think it turned out as well as it could have, still good, but a bit spread thin if that makes since