Peel and cook potatoes until tender. Drain potatoes and whip. Add sugar, eggs, salt, butter, milk and vanilla. Mix well and put in a greased 1 1/2 quart casserole.
Bake in a preheated 325 degree oven for 25 minutes. Place marshmallows and pecans on top and return to oven for about 5 minutes or until brown on top.