Instructions:
Preheat Oven & Combine Ingredients: Preheat your oven to 400°F (200°C). In a high-sided oven-proof pot or large skillet, combine the defrosted frozen meatballs, one jar of marinara or spaghetti sauce, 3 cups of water, one box of bowtie pasta, and 1 teaspoon of Italian seasoning. Stir everything well to combine, ensuring the pasta is as submerged as possible in the liquid.
Initial Bake (Covered): Cover the pot or skillet tightly with a lid or aluminum foil. Bake in the preheated oven for 35 minutes.
Final Bake (Uncovered): Remove the lid or foil. Sprinkle the 1 ½ cups of mozzarella cheese and ¼ cup of grated Parmesan cheese evenly over the casserole. Return the dish to the oven, uncovered, and bake for an additional 10-15 minutes, or until the cheese is melted, bubbly, and lightly golden brown.
Rest & Serve: Once baked, remove the casserole from the oven and let it sit for about 10 minutes before serving. This allows the sauce to thicken slightly and the casserole to set.