In a medium saucepan combine butter, syrup, and cider; heat to boiling, stirring occasionally. Boil gently, uncovered, for 1 minute. Remove from heat; set aside. Place potatoes in a 3-quart rectangular baking dish. Pour butter mixture over potatoes; stir to coat. Cover and bake in a 350 degree F oven for 45 minutes.
Uncover dish; add apples and stir to coat evenly. Bake, uncovered, about 30 minutes or until sweet potatoes are tender, stirring once halfway through baking. Sprinkle with pecans before serving. Makes 10 servings.