Preheat oven to 400°. Spray a 9 X 13 casserole with non-stick spray.
Put pasta, sauce, mozzerella, and most of the parmesan into the prepared dish and combine well. Add the ricotta or cottage cheese in dollops on top. Smooth around a bit with a spoon, and sprinkle the rest of the parmesan on top of that.
Spray a sheet of foil with cooking spray so the cheese won't stick to it, and cover the casserole tightly. Bake for 40 minutes, uncover and bake another 20 minutes. Allow ziti to sit for ten minutes before serving.