Peel the sweet potatoes and slice thinly.
Core the apple and cut into thin slices - (May peel, if desired).
Layer the apples and sweet potatoes into a square baking dish.
Combine applesauce and water and pour over the layered ingredients; sprinkle with cinnamon, if desired.
Cover and bake at 400 degrees for 40 minutes - May be served hot or cold.