In a large bowl, mix the thawed hash browns until evenly combined.
In a separate bowl, whisk the eggs and milk together until frothy.
Incorporate the cooked sausage or bacon, onion, bell pepper, salt, black pepper, and garlic powder into the hash browns. Pour your egg mixture over this blend.
Transfer everything into a greased baking dish, spreading it out evenly.
Sprinkle additional cheese on top.
Bake in the preheated oven for 45-50 minutes, or until the eggs are set and the top is golden brown.
Let it cool slightly before serving. Enjoy!
Notes
This casserole can be made ahead of time. Assemble it the night before and bake it in the morning. Leftovers can be stored in the refrigerator for up to 3-4 days.