Preheat oven to 425°F
Spray a 9x13 baking dish with nonstick cooking spray. I love a deeper casserole dish for this.
Dump it in: Pour the pasta, meatballs, sauce, water and all seasonings into the dish. Stir everything together and push the pasta into the liquid as much as possible. (You'll need 3 cups of water total for the casserole. Fill the sauce jar with some of the water, give it a shake and pour into the baking dish along with the remaining water.)
Bake it: Wrap the dish tightly in foil. Bake for 30 minutes, or until the pasta is tender.
When it's finished baking, remove the foil, stir well, sprinkle the mozzarella cheese evenly over the top and pop it back in the oven until the cheese is melted, about 5-8 minutes.
Serve immediately with a simple side salad and garlic bread for an easy crowd pleasing weeknight dinner.