Because of the starchy potatoes, the resulting donuts are tender in the middle but delightfully crispy on the edges. I think they are perfect without any toppings whatsoever, but some of the brethren are fond of cinnamon sugar and icing, so I make a selection. Try them this weekend, and you might discover a new family favorite!
¼ cup (½ stick) of softened butter
1 cup granulated sugar
1 egg (room temp)
2 tsp. vanilla extract
¾ cup mashed potatoes
¼ cup milk (2% or skim)
2 ¼ cups of all-purpose flour (plus more for the work surface)
2 tsp baking powder
½ tsp. table salt
1 tsp. nutmeg (½ tsp. if grated fresh)
Vegetable shortening or oil for frying
Cinnamon sugar, powdered sugar, icing, etc. as desired
In a medium size bowl, cream the butter and the sugar until fluffy. Add the egg and vanilla and beat until the mixture is glossy. Add the mashed potatoes and milk and beat until well blended (instant potatoes mix in easily, real potatoes may not quite incorporate all the way---no worries!)
In a separate smaller bowl, combine flour, baking powder, salt and nutmeg and whisk until thoroughly blended. Add the dry ingredients to the potato mixture and beat just until evenly combined. The dough will be soft and fairly sticky, rather like cookie dough. Allow to rest in the bowl for 10 minutes.
Generously dust a counter or board (wood is best) with flour and turn the dough out onto the floured counter. Sprinkle the top with flour as well. Flour your hands and press the dough into a rough oval about ½″ thick, or use a floured rolling pin. Cut out donuts using a donut cutter (I like to use a small one, about 2½″ across). Gather up the scraps and press them together into a ball, then flatten again to cut out more donuts. The remaining scraps can be rolled into balls to go in with the donut holes.
Use a Dutch oven or a deep cast iron fryer over medium heat: bring the oil temperature up to 375° F. A thermometer is really necessary here, unless you have a calibrated electric skillet. Fry the donuts three or four at a time, turning once: about 2 to 4 minutes per side, until browned. Transfer the cooked donuts to paper towels to drain. Fry the donut holes at the end all at once, stirring constantly so they are cooked on all sides.
These donuts are just sweet enough that you can enjoy them without any topping or glaze, but you can toss them in cinnamon sugar, sprinkle them with powdered sugar, dip them in a glaze, etc.