Brush off dirt but do not wet skins and prick skins. Roast in a 400 degree oven for 1 hour or a little more until done. Potatoes will caramelize and pull away from the skin so they are very easy peel.

Scoop out warm sweet potatoes into a large bowl. Add melted butter, sugar, cinnamon, and vanilla. Beat with an electric mixer until creamy. The amount of sugar depends on the sweetness of the potatoes. Remember that the marshmallows add sweetness. Beat in egg beaters. If too thick, add a little half in half.

Pour into a buttered casserole dish and bake at 350 until hot and puffy.

Top with marshmallows and bake or broil on low until melted & light brown.