Preheat your oven to 350°F (175°C).
In a large mixing bowl, combine the cooked chicken, broccoli, and rice.
Add the cream of mushroom soup and mix until well combined.
Stir in milk, garlic powder, onion powder, salt, and pepper.
Fold in half of the shredded cheddar cheese.
Transfer the mixture to a greased casserole dish.
Sprinkle the remaining cheddar cheese on top.
Evenly distribute the breadcrumbs over the cheese.
Bake in the preheated oven for 25-30 minutes, until golden brown and bubbly.
Let it cool for a few minutes before serving.