Preheat oven to 350℉ (175℃) and lightly grease a 7x11 or 9x9 baking dish.

In a medium skillet over medium-high heat, brown the sausage until fully cooked through, breaking it into small pieces as it cooks. Remove from heat and drain off any grease as needed. Set aside.

In a medium mixing bowl, whisk together 6 large eggs, ½ cup milk, 1 teaspoon kosher salt, and ½ teaspoon black pepper until well combined.

Layer 16 ounces defrosted hash browns into the greased baking dish, followed with the cooked sausage. Sprinkle 2 cups sharp cheddar cheese over top the sausage and hashbrowns. Pour the egg mixture over the layered casserole. Use a spoon to push the ingredients down to ensure everything is covered with the egg mixture.

Bake for 40-45 minutes or until eggs are set and the casserole is slightly browned. Let rest for 5-10 minutes prior to serving.