powdered (confectioners') sugar
Combine 1/2 cup mashed potatoes and power sugar till is firm enough to roll. The mixture will become very wet; just keep adding powdered sugar. roll out on powdered sugar as you would pie crust on flour to maybe 1/4 inch thick. Spread with creamy peanut butter. Roll into jelly roll cut into small slices about 1/4 of an inch thick pieces.