Heat oven to 325°F. Arrange fruit in ungreased 12x8-inch (2-quart) baking dish.
In medium saucepan, combine brown sugar, cornstarch, nutmeg and apple cider; mix well. Cook over medium heat until bubbly and thickened, stirring frequently. Stir in margarine; cook until melted. Remove from heat; stir in rum. Pour over fruit.
Bake at 325°F. for 25 minutes or until hot and bubbly.