Halal Sausage Hash Brown Breakfast Casserole

Preheat the oven to 375°F (190°C). Grease a 9x13-inch baking dish with butter or cooking spray.
In a large skillet over medium heat, cook the halal sausage, breaking it into crumbles, until browned and cooked through, 5–7 minutes. Drain excess fat.
Spread the thawed, patted-dry hash browns evenly in the prepared baking dish. (Optional: sauté hash browns in the sausage skillet for 3–4 minutes to drive off extra moisture and add light browning.)
Distribute the cooked sausage evenly over the hash browns.
In a mixing bowl, whisk together eggs, milk, salt, pepper, garlic powder, and onion powder until smooth. Stir in bell peppers, spinach, smoked paprika, and red pepper flakes if using.
Pour the egg mixture evenly over the sausage and potatoes. Sprinkle the shredded cheddar evenly on top.
Bake for 35–40 minutes, until the eggs are set and the top is golden and bubbly. If browning too quickly, tent loosely with foil during the last few minutes.
Remove from oven and let rest 5–10 minutes for cleaner slices. Cut into squares and serve warm.
Storage: Refrigerate leftovers in an airtight container up to 4 days, or freeze individual squares up to 2 months. Reheat in the microwave 60–90 seconds or in a 350°F (175°C) oven about 10 minutes.