Follow these simple steps to create your Dump-and-Bake Meatball Casserole:

1. Preheat the oven: Preheat your oven to 375°F (190°C).
2. Prepare the baking dish: Lightly grease a 9×13-inch baking dish or casserole dish.
3. Combine ingredients: In the prepared dish, layer the frozen meatballs, cooked pasta, marinara sauce, Italian seasoning, and garlic powder. Stir gently to combine.
4. Add cheese: Sprinkle half of the mozzarella cheese evenly over the top of the pasta and meatball mixture.
5. Add remaining ingredients: Pour the mixture over the pasta evenly and top with the remaining mozzarella cheese and grated Parmesan cheese.
6. Cover and bake: Cover the dish with aluminum foil and place it in the preheated oven. Bake for 25 minutes.
7. Uncover and finish baking: After 25 minutes, remove the foil and bake for an additional 10 minutes, or until the cheese is bubbly and golden brown.
8. Garnish: Remove the casserole from the oven and let it cool slightly before garnishing with fresh basil or parsley.
9. Serve: Cut into squares and serve hot. Enjoy!

These easy-to-follow steps will help you create an incredible Dump-and-Bake Meatball Casserole without breaking a sweat.