Preheat oven to 375°F (190°C). Spray a 9x13-inch baking dish generously with cooking spray.
In a large mixing bowl, whisk together cream of chicken soup, chicken broth, milk, and onion soup mix until smooth and well combined.
Add uncooked rice, garlic powder, onion powder, salt, pepper, and Italian seasoning to the bowl. Stir until everything is evenly mixed.
Pour the rice mixture into the prepared baking dish and spread evenly.
Sprinkle 1 cup of shredded cheddar cheese over the rice mixture.
Pat chicken breasts dry with paper towels and season both sides lightly with salt and pepper.
Nestle the chicken breasts into the rice mixture, pressing down slightly so they're partially submerged.
Cover the baking dish tightly with aluminum foil.
Bake for 45 minutes, covered.
Remove foil and check that rice is tender and chicken reaches an internal temperature of 165°F. If needed, bake uncovered for an additional 5-10 minutes.
Sprinkle the remaining 1 cup of cheddar cheese over the entire casserole.
Return to oven, uncovered, and bake for 5-7 minutes until cheese is melted and bubbly.
Remove from oven and let rest for 5 minutes before serving.
Garnish with fresh chopped parsley and green onions if desired.