Preheat oven to 375°F. Spray a 9x13 baking dish with olive oil cooking spray.
Add the cooked and drained penne pasta to the baking dish.
Add the tomato & basil marinara sauce, grated parmesan cheese, 1½ tablespoons freshly chopped parsley, garlic powder, onion powder, and salt to the pasta. Stir to combine and coat all the pasta with the sauce and parmesan cheese. Be sure that your pasta is spread out into an even layer.
Place the meatballs in 6 rows of 3 meatballs each into the pasta and sauce. Push the meatballs gently down into the pasta so that they are nestled down but not covered by the pasta.
Top the entire dish of pasta and meatballs with the shredded mozzarella cheese. Bake for 30-35 minutes or until the cheese is melted and lightly browned.
Sprinkle the remaining ½ tablespoon of freshly chopped parsley over the top and serve while still warm.
We’d recommend grating your own cheese. Pre-shredded cheese tends to be coated with a preservative that prevents it from melting well.
Oven temperatures vary and may need to be recalibrated periodically to ensure they are accurate. Make sure to check your casserole at the lower end of the recommended cooking time.