Preheat your oven to 350°F (175°C).
Cook the sausage in a skillet over medium heat until browned.
In a large mixing bowl, combine the eggs, milk, garlic powder, onion powder, salt, and pepper.
In a greased 9x13 inch baking dish, layer the hashbrowns at the bottom.
Evenly distribute the cooked sausage over the hashbrowns.
Pour the egg mixture over the sausage and hashbrowns, then top with shredded cheddar cheese.
Cover with aluminum foil and bake for 30 minutes.
Remove the foil and bake for an additional 15-20 minutes or until the cheese is bubbly and golden.
Let the casserole rest for 10 minutes before serving.