Boil potato until soft.

While hot, peal and remove any imperfections, then mash thoroughly

Add butter, milk, vanilla and salt.

Slowly mix in confectioners' sugar until the mixture has the thickness of stiff bread dough. Depending on the size of the potato, this could take 1 or 2 boxes of sugar.

Roll mixture to 1/4 inch thick on cloth that has been sprinkled with confectioners' sugar.

Spread peanut butter thinly over entire surface. Sprinkle with chopped peanuts (optional).

Starting at 1 edge, roll the dough jelly-roll fashion, and seal the ends.

Place in refrigerator until chilled and firm.

Once firm, cut into 1/2 inch thick disks.

Refrigerate until served.