Old-Fashioned Potato Doughnuts with Coffee Glaze

In a small saucepan, cook potato in lightly salted boiling water, covered, 20 minutes or until tender. Drain the potato and push it through a potato ricer or a sieve into a large bowl. Measure 1 cup lightly packed potato; discard remaining.

Add the sugar and melted butter to the 1 cup potato in the large bowl. Whisk to combine. Whisk in eggs and buttermilk.

Pour at least 4 inches of oil into a large, deep pot, and heat it to 380°. (The oil will rise another 4 inches with the addition of the doughnuts, so make sure your pot is deep enough to contain it.)

Sift 3 cups flour, the baking powder, salt and nutmeg together into a medium bowl. Sift half of the flour mixture into the potato mixture. Stir to combine. Add the rest of the flour and stir until just combined. The dough should be soft and a bit sticky, but if necessary, add another 1/4 cup flour to make it easier to work with. Turn the dough onto a generously floured surface. Sprinkle flour over the dough and, with floured hands, pat the dough out until it is about 1/2 inch thick.

Using a doughnut cutter, cut out 12 doughnuts. Gently transfer each circle to a floured plate to await frying, reserving all holes for a single fry batch.

Add three to four doughnuts (a single snug layer) to the hot oil. Fry them to a deep brown on one side, gently flip them with chopsticks or a pair of tongs, and fry the other side to a deep brown. Remove with a slotted spoon to a wire rack to drain. Bring the oil back to 380° each time before frying the remaining doughnuts, holes and any scraps.

To glaze doughnuts: In a large bowl, stir together coffee and vanilla. Gradually add powdered sugar, whisking until smooth. Dip doughnuts face-down in the glaze, turn them up, and set them on a rack to let glaze drip off and set.