Nothing beats a fresh doughnut! This thrifty recipe comes from the New England chapter of the United States Regional Cookbook, Culinary Arts Institute of Chicago, 1947. Chilling time not included in preparation time.
Beat potatoes, eggs, sugar, melted butter together; add nutmeg and milk and stir.
Add sifted ingredients and stir until just blended; chill.
Preheat the oil to 375F in a large saucepan or stockpot.
Place about 1/3 of the dough at a time on a lightly floured board, sprinkle surface lightly with flour and roll to 3/8" thickness (the dough should be just stiff enough to handle; the softer the dough, the more tender the doughnut).
Cut with a doughnut cutter dipped in flour.
Fry until golden brown.
Drain on paper towels for a few seconds; roll in granulated or confectioners' sugar, if desired.