Preheat the oven to 375°F (190°C). Grease a 9×13-inch baking dish with butter or non-stick spray.
In a medium bowl, combine the stuffing mix with 1 cup chicken broth. Stir and let sit for a few minutes to absorb the liquid.
In another bowl, whisk together the cream of chicken soup, sour cream, garlic powder, onion powder, and black pepper until smooth.
Place chicken breasts evenly in the baking dish. Spread the creamy mixture over the chicken. Spoon the hydrated stuffing evenly on top.
Drizzle melted butter over the stuffing. Cover with foil and bake for 30 minutes.
Remove foil, sprinkle shredded cheese (if using), and bake uncovered for another 10–15 minutes or until the chicken reaches 165°F (75°C) and the top is golden brown.
Let the casserole rest for 5 minutes before serving. Garnish with chopped parsley.
