Bring sweet potatoes and water to cover to a boil, and cook 20 to 30 minutes or until tender; drain. Peel potatoes, and place in a mixing bowl.
Heat milk and next 3 ingredients in a saucepan over medium heat, stirring until butter melts and sugar dissolves. (Do not boil.) Stir in orange juice, spices, and salt.
Beat potatoes at medium speed with an electric mixer until mashed. Add milk mixture, beating until smooth. Spoon half of mashed sweet potatoes into a lightly greased 13- x 9-inch baking dish; top evenly with half of marshmallows. Spread remaining mashed potatoes over marshmallows.
Bake at 350° for 25 minutes. Top with remaining half of marshmallows, and bake 8 to 10 more minutes or until marshmallows are golden.
Beebe Roberts, Birmingham, Alabama