Start by boiling your potatoes until tender. Do not let them get mushy.
Let cool and peel.
Dice up peeled potatoes into cubes.
Grease a glass baking dish and pour 3/4 of your applesauce into the bottom.
Place diced potatoes on top.
Sprinkle potatoes with 1/2 a cup of brown sugar.
Pour the remaining applesauce on top, and spoon butter on top of that.
Sprinkle with remaining brown sugar.
Bake at 375 degrees for 30 minutes.
Pull from oven and place marshmallows on top.
Bake for an additional 5 minutes.
Serve an enjoy.