Preheat oven to 375�F. Lightly grease a 9" x 13" baking dish.
Place sausage in a large, deep skillet. Cook over medium-high heat until evenly brown. Drain, crumble, and set aside.
In the prepared baking dish, stir together the shredded potatoes and butter. Line the bottom and sides of the baking dish with the mixture. In a bowl, mix the sausage, Cheddar cheese, onion, cottage cheese, and eggs. Pour over the potato mixture.
Bake for 1 hour in the preheated oven, or until a toothpick inserted into center of the casserole comes out clean. Let cool for 5 minutes before serving.