Preheat oven to 375 degrees F. Spray a 8x10- inch baking dish with nonstick cooking spray; set aside.

Peel and dice potatoes then place in a large pot. Fill with water until potatoes are completely covered. Bring to a boil over medium-high heat and let boil for 20 minutes or until fork tender.

Drain potatoes and place in a large mixing bowl and mash with a potato masher or hand mixer. Add yogurt, milk, butter, garlic powder, salt and pepper; mix to combine.

Spread mashed potatoes in an even layer in prepared pan and top with cheddar cheese and cooked bacon.

Cook, uncovered, for 25-30 minutes or until bacon is crisp and cheese is melted. Garnish with chives before serving.