Sausage and Cheese Breakfast Casserole (no bread)

0 This recipe can be baked overnight in a 6-quart slow cooker or baked right away in a 3-quart baking dish.Slow cooker: If using a slow cooker, line it with a foil collar. Do this by folding a sheet of foil in thirds and wrapping it all the way around the inside of the bowl of the slow cooker. (This is where the heating element is on most slow cookers, so this extra layer will prevent the casserole from overcooking.) Rub the inside of the slow cooker and the foil collar with the softened butter.Oven: Preheat the oven to 375 degrees F. Rub the inside of a 3-quart baking dish with softened butter.
2 In a large skillet over medium heat, cook the breakfast sausage, breaking it apart until cooked through and browned, 5 to 7 minutes. 
3 Transfer the cooked sausage to a paper towel-lined plate to let it drain.
4 Place the sweet potatoes in a microwave-safe bowl. Add 1 tablespoon of water and cover the bowl with a damp paper towel. Microwave on high until sweet potatoes are tender, about 3 minutes. 
5 Spread the sausage and sweet potatoes out in the bottom of the slow cooker or baking dish.
6 Whisk together eggs, milk, salt, and black pepper. Add the cheese and stir to combine.
7 Pour the egg / cheese mixture over the sweet potatoes and sausage.
8 Slow cooker: Place two layers of paper towels underneath the slow cooker lid before you close the slow cooker. (The paper towels will absorb moisture that collects on the lid, preventing it from dripping down onto the casserole and making it seem soggy at the end of cooking.) Cook on high for 2 hours. Serve immediately or let the slow cooker switch to warm for up to 6 hours. (Note: This is to allow you to let it sit overnight. Check the manual of your slow cooker to be sure that the warm function will stay on for the full 6 hours so it stays warm until morning.)
9 Oven: Bake the casserole until the center is set but still wobbly, 35 to 40 minutes. 
11 Let the casserole cool for 5 minutes. Slice and serve.