Peanut Butter Pinwheel Candy

Bahan-bahan (40 porsi)

• ⅓ cup mashed potatoes (about 1 large russet potato)
• ½ cup unsalted butter softened
• 2 teaspoons vanilla extract
• 1 pinch salt
• 6 -7 cups powdered sugar (plus additional for dusting)
• Creamy peanut butter (for filling)