Boil potatoes in water to cover 25 minutes or until tender. Cool slightly and peel.
Combine potatoes, sugar, cinnamon, and butter in a large bowl. Mash well with a potato masher. Stir in next 4 ingredients.
Spoon into a buttered 11- x 7-inch dish. Sprinkle evenly with marshmallows. Bake at 350° for 20 minutes or until marshmallows are lightly browned.