Creating Chicken Parmesan Casserole is simple! Follow these steps to bring this comforting dish to life:

1. Preheat the Oven: Preheat your oven to 375°F (190°C).
2. Prepare Chicken: Cut the chicken breasts into bite-sized pieces. Season with salt, pepper, garlic powder, and onion powder.
3. Cook Chicken: In a large skillet over medium heat, add a splash of olive oil. Cook the seasoned chicken pieces until they are golden brown and cooked through, about 5-7 minutes.
4. Mix Ingredients: In a large mixing bowl, combine the cooked chicken, marinara sauce, dried oregano, and cooked pasta (if using). Stir well to combine.
5. Layer the Casserole: In a greased 9×13-inch baking dish, spread half of the chicken mixture evenly across the bottom.
6. Add Cheese: Sprinkle half of the mozzarella and half of the Parmesan cheese over the chicken mixture.
7. Repeat Layers: Add the remaining chicken mixture on top, followed by the remaining mozzarella and Parmesan cheese.
8. Bake: Cover the dish with aluminum foil and bake in the preheated oven for 25 minutes. Remove the foil and bake for an additional 15-20 minutes, or until the cheese is bubbly and golden.
9. Let It Rest: Once done, remove the casserole from the oven and let it rest for about 5 minutes before serving. This allows the flavors to meld together.
10. Garnish and Serve: Top with fresh basil if desired before serving.

By following these steps, you’ll have a delicious Chicken Parmesan Casserole that’s sure to please everyone at your table.