Preheat your oven to 350°F (175°C).
In a large pot, cook rice according to package instructions until tender.
In a large mixing bowl, combine cooked rice, broccoli, cheddar cheese, cream of mushroom soup, milk, garlic powder, onion powder, salt, and pepper.
Transfer the mixture into a greased 9x13 inch baking dish, spreading it evenly.
Sprinkle breadcrumbs evenly on top of the mixture.
Cover with aluminum foil and bake for 25 minutes.
Remove the foil and bake for an additional 15 minutes, or until the top is golden brown.
Let the casserole rest for 5-10 minutes before serving.