Creating the Dump-and-Bake Chicken Parmesan Casserole is straightforward and easy to follow. Here are the clear steps to guide you:

1. Preheat the Oven: Begin by preheating your oven to 375°F (190°C).
2. Prepare the Chicken: Take the chicken breasts and place them in a greased 9×13-inch baking dish.
3. Season the Chicken: Sprinkle the garlic powder, oregano, basil, salt, and pepper evenly over the chicken.
4. Add Marinara Sauce: Pour the marinara sauce over the seasoned chicken, completely covering it.
5. Layer Cheese: Sprinkle half of the grated Parmesan and all of the shredded mozzarella evenly over the sauce.
6. Add More Cheese: Finish off by topping with the remaining Parmesan cheese for a rich finish.
7. Optional Crunch: For an added crunchy topping, you can sprinkle breadcrumbs over the cheese layer.
8. Bake: Cover the dish with aluminum foil and bake in the preheated oven for 30 minutes. After 30 minutes, remove the foil and bake for an additional 15 minutes, or until the chicken is cooked through and the cheese is bubbly and golden brown.
9. Check for Doneness: Ensure the internal temperature of the chicken reaches 165°F (75°C) before serving.
10. Garnish and Serve: Once cooked, remove from the oven, and garnish with freshly chopped parsley if desired.

These simple steps make it easy to whip up this delicious casserole in no time!