In a large skillet over medium heat, cook the breakfast sausage until browned, breaking it up into small pieces as it cooks. Remove from heat and drain any excess fat.
In the same skillet, add the diced onion and red bell pepper. Sauté for about 3-4 minutes until softened.
In a large mixing bowl, combine the cooked sausage, sautéed onion and bell pepper, thawed hash browns, and half of the shredded cheddar cheese. Mix well.
In another bowl, whisk together the eggs, milk, garlic powder, onion powder, salt, and pepper until well combined.
In a greased 9x13-inch baking dish, spread the sausage and hash brown mixture evenly. Pour the egg mixture over the top, ensuring it coats the hash browns. Sprinkle the remaining cheddar cheese on top.
Bake in the preheated oven for 30-35 minutes, or until the casserole is set in the middle and the top is golden brown.
Once baked, allow the casserole to cool for a few minutes before slicing. Garnish with freshly chopped parsley for a pop of color.
Notes
Allow the casserole to cool slightly before slicing for easier serving.