Preheat oven to 375°F
In a 9×13 baking dish, add dry pasta, frozen meatballs, marinara sauce, and water. Stir to combine. Make sure all noodles are covered with liquid (add more water if needed)
Cover tightly with foil and bake for 40 minutes
Remove foil, sprinkle mozzarella evenly over the top
Bake uncovered for 10 more minutes, until cheese is melted and bubbly
Let rest 5–10 minutes before serving
