Preheat oven to 350 Grease 11/2 quart casserole dish.

Peel and cut Sweet potatoes in chunks. Boil and cook in 4quart pot until tender for 20-30 minutes. Drain.

Stir butter in potatoes until melted and mashed. Stir in sugars.

Mix milk, nutmeg and vanilla then stir into potatoes and spoon into casserole dish.

Bake 1hr then sprinkle marsh,allows on top and let bake for 7-10mins or until melted and brown.