Begin by heating your oven to 350°F (175°C).
In a large non-stick skillet, brown the sausage over medium heat until fully cooked, ensuring there is no pink remaining. Drain off any rendered fat.
Blend the softened cream cheese with the cooked sausage until thoroughly combined. Set this mixture aside.
Using the same skillet, cook the frozen shredded hash browns until they begin to develop a golden crust. Once lightly browned, transfer them to the bottom of a greased 9×13-inch baking dish, spreading evenly.
Layer the sausage and cream cheese mixture on top of the hash browns, then sprinkle the shredded cheddar cheese uniformly over the surface.
In a separate mixing bowl, whisk together the eggs, milk, salt, pepper, garlic powder, and onion powder until well incorporated.
Pour the egg mixture over the layers in the baking dish, ensuring even coverage.
At this point, the casserole may be covered and placed in the refrigerator if baking at a later time.
Place the dish in the preheated oven and bake, uncovered, for 40 to 50 minutes, or until the center is set and the top is lightly golden.