Preheat oven to 375°F (190°C) and grease a muffin tin.
In a bowl, mix mashed potatoes, egg, sour cream, garlic powder, salt, and pepper.
Spoon the mixture into the muffin tin, filling each cup.
Sprinkle shredded cheese, bacon, and green onions on top.
Bake for 20-25 minutes or until golden brown.
Let cool for a few minutes before serving.
