1 lb. sweet potatoes or yams (about 3 med.)
1/2 c. sour cream
1 egg yolk
1/2 tsp. salt
1/4 tsp. ground mace
3/4 c. mini marshmallows

Cook sweet potatoes until tender, remove skin. Beat sweet potatoes, sour cream, egg yolk, salt and mace in a small mixing bowl on medium speed until smooth. Pour into buttered 1 quart casserole, top with marshmallows. Cook uncovered in 350 degree oven until marshmallows are puffed and golden brown, about 30 minutes. 4 servings.