Preheat the Oven: Preheat your oven to 375°F (190°C). Grease a 9x13-inch baking dish with cooking spray or butter.
Combine Ingredients: In a large mixing bowl, combine the rice, cream of mushroom soup, cream of chicken soup, chicken broth, garlic powder, onion powder, salt, and black pepper. Stir until well blended.
Assemble the Casserole: Pour the rice mixture into the prepared baking dish. Spread the shredded chicken evenly over the top. If using frozen peas and carrots, scatter them over the chicken.
Bake: Cover the dish tightly with aluminum foil and bake for 40-50 minutes, or until the rice is tender and the liquid is absorbed.
Add Cheese and Toppings: Remove the foil and sprinkle shredded cheddar cheese evenly over the casserole. Add breadcrumbs if desired for extra crunch. Return to the oven and bake uncovered for 10-15 minutes, or until the cheese is melted and bubbly.
Serve: Let the casserole rest for 5-10 minutes before serving. Garnish with fresh parsley if you like.