Preheat the oven to 350. Prepare a 9" x 13" pan with cooking spray; set aside. Place cooked ziti in a mixing bowl. Stir in cottage cheese and half of the mozzarella cheese. Mix well. Cover the bottom of prepared pan with half the spaghetti sauce. Spoon the ziti mixture on top. Then spread remaining spaghetti sauce over ziti mixture. Sprinkle with the parmesan cheese and top with remaining mozzarella cheese. Bake for 20 minutes, or until cheese has melted.