Heat oven to 400°F (200°C). Grease a 9x13-inch dish.
1 tbsp olive oil
In the dish, stir together pasta, marinara, water, 2 cups mozzarella, half the Parmesan, and pepper. Push pasta under the liquid. Taste and salt if needed.
1 lb ziti, 24 oz marinara sauce, 3 cups water, 12 oz mozzarella, 1 oz parmesan, ¼ tsp black pepper, salt
Dollop cottage cheese on top. Stir 2 or 3 times, leaving pockets of cottage cheese.
16 oz cottage cheese
Sprinkle on remaining Parmesan. Cover tightly with foil, sealed all around. Bake 40 minutes.
Uncover. Top with remaining 1 cup mozzarella. Bake uncovered 20 minutes, until bubbling.
Optional: broil 2 to 3 minutes until browned in spots.
Rest 10 minutes before serving.