
Place potatoes in a Dutch oven; cover with water. Bring to a boil. Reduce heat; cook, uncovered, 10-15 minutes or until tender. Drain potatoes; return to pan.
Mash potatoes, gradually adding cream cheese, sour cream and butter. Stir in milk and seasonings. Transfer to a greased 13x9-in. baking dish. If desired, sprinkle with cheese and bacon. Refrigerate, covered, up to 1-2 days.
Preheat oven to 350°. Remove potatoes from refrigerator and let stand while oven heats. Bake, covered, 30 minutes. Uncover; bake 10 minutes longer or until heated through. If desired, sprinkle with green onions.