Heat oven to 350°F. Spray 13x9-inch (3-quart) glass baking dish with cooking spray. Place potatoes in large microwavable bowl. Microwave uncovered on High 6 to 8 minutes, stirring twice, until thawed and potatoes are hot.
Stir in remaining ingredients. Spoon into baking dish. Bake uncovered 30 to 35 minutes or until hot in center and bubbly around edges.