These are best eaten slightly warm.

　　

Ingredients

makes about 36

　　8 ounces russet potatoes, peeled and sliced

　　1/4 cup warm water, plus 6 tablespoons water

　　1 tablespoon active dry yeast

　　1 cup milk, scalded

　　1/4 cup solid vegetable shortening

　　3/4 cup granulated sugar

　　1 teaspoon salt

　　2 large eggs, lightly beaten

　　5 cups all-purpose flour, plus more, if needed, for the dough and work surface

　　2 quarts vegetable oil, plus more for the bowl

　　4 cups confectioners’ sugar

　　1 teaspoon pure vanilla extract

　　1/2 teaspoon ground cinnamon

　　

Step 1

Have ready 2 parchment-lined baking pans. Place the potatoes in a small saucepan, cover with cold water, and bring to a boil over high heat. Cook until tender, about 15 minutes. Drain in a colander. Pass the potatoes through a potato ricer or food mill and into a medium bowl; set aside.

　　

Step 2

Place 1/4 cup warm water in a small bowl; sprinkle with the yeast, stir gently, and let stand until creamy, 5 to 10 minutes. Using an electric mixer fitted with the paddle attachment, combine the milk, shortening, 1/4 cup sugar, and salt. Let stand until cooled to just warm. Add the yeast mixture, reserved potatoes, and eggs; beat until combined.

　　

Step 3

Switch to the dough hook. Add 5 cups flour, and mix on medium-low speed until combined, adding more flour if necessary, until a smooth and elastic dough is formed, about 5 minutes. Transfer the dough to a large, lightly greased bowl; cover. Let stand in a warm place until the dough is doubled in size, about 55 minutes.

　　

Step 4

Transfer the dough to a lightly floured surface. Roll out to 1/2 inch thick. Using a 2 1/2-inch-diameter doughnut cutter, cut and place on prepared baking pans. Loosely cover with plastic wrap; let stand in a warm place until the dough has risen by about one-third, about 30 minutes.

　　

Step 5

Combine the confectioners’ sugar, vanilla, and remaining 6 tablespoons water in a medium bowl, stirring until smooth; set aside. In a medium bowl, whisk together the remaining 1/2 cup granulated sugar and cinnamon until well combined; set aside.

　　

Step 6

In a large, low-sided saucepan over medium heat, heat the oil until a deep-fry thermometer registers 375°F. Drop the doughnuts into the oil; fry in batches until golden, 1 to 2 minutes per side. Transfer to several layers of paper towel to drain. Place the drained doughnuts on a wire rack set over a baking pan. Dip half the doughnuts in the glaze; return to the wire rack. Roll the remaining doughnuts in the cinnamon-sugar mixture until well coated.

　　Reprinted with permission from The Martha Stewart Living Cookbook: The New Classics by Martha Stewart Living Magazine, copyright © 2007. Published by Clarkson Potter, a division of The Crown Publishing Group.Buy the full book from Amazon.