Preheat oven to 350ºF. Lightly spray a 9x13-inch pan with cooking spray.
In a large skillet, cook sausage until no longer pink. Drain fat.
In a large bowl, toss together tater tots, cooked sausage and cheeses. Pour into a lightly greased 9x13-inch pan.
Whisk together eggs, salt, pepper, garlic powder, onion powder and milk. Pour over tater tot mixture.
Bake uncovered for 60 - 70 minutes, or until eggs are set.
