1 small red or white potato-skin left on
1 18 ounces jar Peanut Butter
1 2 lb bag Powdered Sugar
1 teaspoon Vanilla flavoring, real or imitation
Boil potato until tender. Remove skin. Mash well with fork. Gradually add powdered sugar (reserving some for pastry board) and vanilla until a stiff dough forms. Roll out onto powdered sugar covered pastry board, to the size of 13×9 rectangle. Spread with peanut butter to within 1/2 inch of edge of dough. Roll up length-wise to form a roll 13 inches long. Wrap dough in wax paper and refrigerate at least 2 hours. Then slice into pieces. Thickness is up to you as this is a really rich candy.
NOTE
Depending on the size of potato, and the humidity in the air will determine how much powdered sugar you will need.