01 -
Preheat the oven to 425 degrees Fahrenheit (220 Celsius).
02 -
In a 9x13-inch baking dish, mix the water, marinara sauce, and crushed red pepper flakes until well combined. Add the uncooked pasta, and stir until evenly coated in the sauce.
03 -
Arrange the frozen meatballs evenly over the top, so they're at least half covered in sauce. Cover the dish tightly with aluminum foil.
04 -
Bake for 30 minutes, remove the foil, and stir the mixture gently but thoroughly. Check the pasta for doneness. It should be cooked to al dente (tender but firm). If needed, re-cover and bake for an additional 5-10 minutes.
05 -
Once the pasta is cooked, stir in 1 cup of mozzarella cheese until melted and evenly distributed. Sprinkle the remaining cup of mozzarella over the top of the casserole.
06 -
Return the dish to the oven, uncovered, and bake for another 10-15 minutes or until the cheese on top is melted and bubbly.
07 -
Let the casserole rest for 5-10 minutes before serving. Garnish with fresh parsley and enjoy!