Preheat the oven to 375°F (190°C) and grease a baking dish. Cook the sausage until browned, then drain the excess grease.
In the same skillet, cook the onions and peppers for about 5 minutes until slightly softened.
Whisk together the eggs, milk, chili powder, smoked paprika, garlic powder, salt, and pepper.
Stir the sausage, vegetables, hash browns, and cheese into the egg mixture. Pour everything into the prepared baking dish.
Bake for 40 to 45 minutes until the eggs are fully set and the cheese is golden on top.
Allow the casserole to cool for 10 minutes before slicing. Freeze individual portions after they have cooled completely.