In a large skillet, cook sausage over medium heat until no longer pink; drain. In a large bowl, combine the soup, milk, onion, onion and garlic powder, salt and pepper.
In an sprayed 9 x 13-in. baking dish, layer half the potatoes, soup-sausage mixture and cheese,; repeat layers.
Cover and bake at 350° for 1-1/2 hours or until potatoes are tender.