Wash and bake the sweet potatoes, as for sweet potatoes Nature.
When cooked, cut in half and remove pulp from skins with a spoon.
Mash, then add the remaining ingredients except the marshmallows.
Salt and pepper to taste.
Mash all together.
Place mixture in a buttered microwave-safe pie plate.
Cover with the marshmallows.
Microwave, uncovered, 5 minutes at HIGH.