Potato Hamburger Buns (Bread Machine Dough)

Ingredients

• 1 medium russet potato (7-8 oz)
• ¾ cup + 1 tablespoon milk (any fat content)
• 1 large egg
• ¼ cup unsalted butter (chopped)
• 2 tablespoons granulated sugar
• 1½ teaspoon table or sea salt
• 3 ⅓ cups bread flour
• 1 ½ teaspoons instant yeast
• 1 tablespoon milk