1. Preheat the oven to 375°F (190°C). Lightly grease a 9×13-inch baking dish with 1 tablespoon of the olive oil.

2. Add the uncooked long-grain white rice to the prepared baking dish. Pour in the chicken broth and marinara sauce, then stir in the diced tomatoes, onion, red bell pepper, Italian seasoning, garlic powder, onion powder, smoked paprika, kosher salt, and black pepper until everything is evenly combined and the rice is submerged.

3. Cover the baking dish tightly with aluminum foil and bake for 40 minutes, until the rice is mostly tender and the mixture looks thick and saucy.

4. Carefully remove the foil and stir the rice. Nestle the frozen fully cooked mini meatballs evenly over the top, pressing them slightly into the rice mixture.

5. Sprinkle half of the shredded mozzarella and half of the shredded sharp cheddar over the rice and meatballs. Drizzle the remaining 1 tablespoon olive oil over the top, cover again with foil, and bake for 20 minutes more, until the meatballs are heated through and the rice is fully tender.

6. Remove the foil and top the casserole with the remaining mozzarella and cheddar, plus all of the grated Parmesan. Return to the oven, uncovered, for about 10 minutes, or until the cheese is melted, bubbly, and lightly golden.

7. Let the casserole rest for 10 minutes before serving. Sprinkle with chopped fresh parsley and enjoy hot.