Add pasta, marinara and water to a 9x13-inch casserole dish. Stir to combine.
Add meatballs on top of pasta. Do NOT stir.
Cover with aluminum foil.
Place on the middle rack of the oven. Bake for 40 minutes. Remove from the oven and uncover.
Sprinkle mozzarella cheese over the top of the meatballs.
Return to the oven for 10-15 minutes to melt the cheese. Cover if you do not want the cheese to brown. Do not cover if you want a golden brown cheesy top.
Let rest for 5-10 minutes then serve.
Notes
If your pasta is sticking up above the sauce level it isn’t going to cook. Get all the pasta down under the liquid. Add a little more water, if necessary.
Do not stir the meatballs and pasta together before cooking. You want the pasta to be below the meatballs, fully submerged in the cooking liquid. The finished dish also looks better with meatballs on top.
Serve with garlic french bread and an Italian salad