Preheat your oven to 350°F (175°C).
In a large mixing bowl, combine broccoli, cooked rice, cream of mushroom soup, milk, garlic powder, and half of the cheddar cheese.
Season the mixture with salt and pepper to taste, mixing well once more.
Transfer the mixture to a greased 9x13-inch baking dish, spreading it evenly.
Sprinkle the remaining cheddar cheese on top, followed by the breadcrumbs.
Bake in the preheated oven for 25-30 minutes or until bubbly and the top is golden brown.
Remove from the oven and let cool for a few minutes before serving.