6 cups powdered sugar, plus extra if needed
1/2 cup mashed russet potato (about 1 large potato), cooled
1/3 cup creamy peanut butter
1 tablespoon milk
1 teaspoon vanilla extract
1/8 teaspoon salt
In a large bowl, beat mashed potato, milk, vanilla, and salt with an electric mixer for 2 minutes.
Mix in powdered sugar, 1 cup at a time, until dough forms. If needed, add more powdered sugar, 1 tablespoon at a time, until dough is thick (slightly thicker than cookie dough).
Form dough into a ball and dust with powdered sugar. Roll dough into a 1/8-inch thick rectangle between two sheets of parchment paper. Trim to 10×12 inches.
Generously sprinkle powdered sugar over dough. Place another sheet of parchment paper on top, then invert the dough. Discard the top parchment paper.
Spread peanut butter evenly over the dough. Roll dough tightly, jelly-roll style, using parchment paper to guide it. Wrap in parchment and freeze for 1 hour.
Cut into 1/4-inch thick slices and serve. Store leftover candy in an airtight container in the refrigerator. Enjoy!
