Preheat oven to 350 degrees. Grease a 9 x 13 inch baking dish.
In a skillet, cook sausage until fully cooked and drain off any excess grease.
In a bowl, combine the hash browns, salt, and pepper together. Add in the cream cheese and gently mix in until evenly distributed throughout the hash browns.
Spread the hash browns into the bottom of the prepared 9×13 baking dish. Sprinkle the cooked sausage over the hash browns followed by half (4 oz) of the cheddar cheese.
In a separate bowl, place the flour in the bowl and slowly add milk while whisking to keep the mixture smooth until all milk is added. Add the eggs into the mixture and whisk until smooth. Pour the egg mixture over the top of the cheese in the baking dish.
Sprinkle the remaining cheese over the top of the casserole.
Bake at for 35-45 minutes or until a knife inserted into the center of the dish comes out clean.