Add 1 cup shredded cheddar cheese, potato flakes and garlic powder and stir gently. Fluff with a fork; do not whip.
Let sit for 2–3 minutes to melt cheese and thicken. Fold in ½ cup sour cream, 3 tablespoons bacon and 3 tablespoons minced chives/green onions. Garnish with remaining cheddar cheese, sour cream, bacon and minced chives or green onions.