Boil sweet potatoes until tender.
Peel and mash until more or less lumpless. Add brown sugar, orange juice and rind, bourbon, butter or margarine, and pumpkin pie spice. Mix well. Spread in shallow dish (10 inch deep dish pie plate works well).
Bake 30 minutes in a 350 degree F (175 degrees C) oven. Top with marshmallows and broil very briefly.