Preheat your oven to 350°F (175°C). Lightly grease your 9x13-inch baking dish with butter or non-stick spray to prevent sticking.
In a skillet over medium heat, cook the crumbled turkey sausage until it is thoroughly browned and no longer pink, about 5-7 minutes. Drain any excess fat, then set the sausage aside to cool slightly.
In a large mixing bowl, whisk together the softened cream cheese, eggs, and milk until the mixture is smooth and creamy. This blend will add moisture and richness to our casserole.
Add the thawed hash browns, cooked turkey sausage, shredded cheddar cheese, garlic powder, onion powder, salt, and pepper into the cream cheese and egg mixture. Stir everything together gently until well combined. Be careful not to overmix as you want to keep some texture.
Pour the mixture into the prepared baking dish, spreading it evenly. If you like, sprinkle the chopped green onions on top for a pop of color and fresh flavor. Bake uncovered for 45-55 minutes, or until the casserole is set in the center and the top is golden brown.
Allow the casserole to cool for about 5 minutes before serving. This dish pairs perfectly with fresh fruit or a light salad. For a complete meal, consider serving alongside Steak And Potatoes for a filling dinner option.