6-8 cups powdered sugar
2/3 cup peanut butter
Place potato in a small pan and cover with water. Cook until very tender. Drain and place in a large bowl. Use a hand mixer to beat the potato until it is lump-free. Add 4 cups of powdered sugar and beat until mixed well. Continue to mix powdered sugar in 1 cup at a time until thick. (It should have the consistency of putty or cookie dough. Place on a large piece of waxed paper that has been lightly coated with powdered sugar. Sprinkle some more powdered sugar on top. Roll potato mixture out into a 1/4-inch thick rectangle. Spread evenly with peanut butter. Starting at a long side, roll up tightly like you would cinnamon rolls. Wrap in wax paper, cut in half and place both pieces in a large ziptop bag. Refrigerate at least 30 minutes or until ready to serve. Remove wax paper and cut into 3/4-inch slices.