Creating this Chicken Parmesan Casserole is straightforward. Follow these easy steps:

1. Preheat the oven to 375°F (190°C) and grease a large casserole dish.
2. Cook Chicken: If not already done, cook the chicken breasts in boiling water or pan-sear them until cooked through. Shred the chicken.
3. Mix Chicken and Sauce: In a large bowl, combine the shredded chicken with 2 cups of marinara sauce. Stir in Italian seasoning, garlic powder, salt, and pepper.
4. Prepare the Pasta: In a separate bowl, mix the cooked pasta with the remaining marinara sauce.
5. Layer Ingredients: Spread half the pasta mixture in the greased casserole dish. Layer half of the chicken mixture on top, followed by half of the mozzarella. Repeat the layers with the remaining pasta, chicken mixture, and mozzarella cheese.
6. Sprinkle Parmesan: Top the casserole with grated Parmesan cheese for an extra layer of flavor.
7. Bake: Place the casserole in the preheated oven and bake for 35-40 minutes, or until the cheese is melted and bubbling.
8. Cool: Remove from the oven and let it cool for 10-15 minutes before serving.
9. Garnish: Optionally, sprinkle fresh basil on top for a pop of color and freshness.

These steps will guide you in preparing a delightful Chicken Parmesan Casserole that is not only incredible but also straightforward enough for any home cook!