Preheat the oven to 350°F (175°C). Grease a 9x13-inch baking dish with butter or nonstick spray.
In a large skillet over medium heat, brown the sausage until fully cooked. Drain any excess fat.
Reduce heat to low and stir in the softened cream cheese until melted and combined with the sausage. Remove from heat and set aside.
Spread the thawed hash browns evenly in the prepared baking dish. Drizzle with melted butter and sprinkle lightly with salt and pepper.
Spoon the sausage-cream cheese mixture evenly over the hash browns.
Sprinkle shredded cheddar cheese evenly over the top.
In a medium bowl, whisk together eggs, milk, garlic powder, onion powder, salt, and pepper until smooth.
Slowly pour the egg mixture evenly over all the layers in the dish. Gently tap the dish on the counter to help it settle.
Place in the preheated oven and bake for 40–45 minutes, or until the eggs are set and the top is golden brown.
Let rest for 5–10 minutes before slicing. Garnish with green onions or parsley if desired.
