Preheat the oven to 350°F (175°C).
In a large mixing bowl, combine shredded chicken, broccoli, cream of chicken soup, milk, garlic powder, onion powder, salt, and pepper.
Mix well until all ingredients are coated.
Transfer the mixture into a greased baking dish.
Sprinkle shredded cheddar cheese evenly on top.
In a small bowl, mix breadcrumbs with olive oil until well combined.
Spread the breadcrumb mixture over the cheese layer.
Bake in the oven for 30 minutes or until the top is golden brown.
Remove from the oven and let it cool for a few minutes.
Serve warm and enjoy your delicious casserole!