Preheat oven to 375°F (190°C) and grease a 9x13-inch baking dish.

In a large skillet, brown the ground beef and onions over medium-high heat for 7-10 minutes, then drain excess fat.

Reduce heat to medium, stir in cream of mushroom soup and sour cream, then add garlic powder, onion powder, salt, and black pepper.

Mix thawed hashbrowns with melted butter and 1 cup cheddar cheese until well coated.

Layer half of the hashbrown mixture in the baking dish, add beef mixture, then remaining hashbrowns and top with an additional cup of cheddar cheese.

Bake uncovered for 35-40 minutes until edges are bubbling and the top is golden brown.

Let rest for 5-10 minutes before serving.