This is a very old candy recipe.
Combine the potato, salt and vanilla in a four quart mixing bowl. Sift the confectioners’ sugar over the potato, stirring and adding about one cup at a time. The mixture will liquefy when the first sugar is added, then gradually begin to thicken. When it becomes the consistency of stiff dough, knead it even though all the sugar has not been added (add more sugar if needed). After kneading, cover the mixture with a damp cloth; chill until a small spoonful can be rolled into a ball. Shape into small ½-inch balls. Dip the balls into melted chocolate, then roll in peanuts or coconut.