Preheat your oven to 350°F.

In a large skillet, brown the sausage over medium heat, breaking it into crumbles as it cooks. Drain any excess grease and set the sausage aside.

Grease a 9x13-inch casserole dish with cooking spray or butter. Spread the shredded hashbrowns evenly across the bottom of the dish to create the base layer.

Sprinkle the cooked sausage evenly over the hashbrowns. If using vegetables, scatter them on top of the sausage layer.

In a mixing bowl, whisk together the eggs, milk, salt, pepper, and garlic powder until well combined. Pour the egg mixture evenly over the sausage and hashbrown layers.

Top the casserole with the shredded cheese, ensuring it is spread evenly across the surface.

Place the casserole in the preheated oven and bake for 40-50 minutes, or until the center is set and the top is golden brown. To check for doneness, insert a knife into the center—it should come out clean.

Let the casserole rest for 5-10 minutes before slicing and serving.