Making Hashbrown Breakfast Casserole is an easy and enjoyable process. Just follow these steps:

1. Preheat Oven: Begin by preheating your oven to 350°F (175°C).
2. Prepare Baking Dish: Grease a 9×13 inch baking dish with cooking spray or butter.
3. Layer Hashbrowns: Spread the frozen hashbrowns evenly in the greased baking dish.
4. Add Onion and Sausage: Sprinkle the chopped onions and cooked sausage evenly over the hashbrowns.
5. Add Cheese: Sprinkle the shredded cheddar cheese over the sausage and onions for a delicious cheesy layer.
6. Whisk Eggs and Milk: In a large bowl, whisk together the eggs, milk, garlic powder, salt, and black pepper until fully combined.
7. Combine Ingredients: Carefully pour the egg mixture evenly over the hashbrown, sausage, and cheese layers in the baking dish.
8. Bake: Place the baking dish in the preheated oven and bake for 45-50 minutes or until the eggs are set.
9. Cool and Serve: Allow the casserole to cool for about 5-10 minutes before cutting into squares and serving.

These straightforward steps will help you create a Hashbrown Breakfast Casserole that is sure to impress everyone at the table.