2 cups sugar
3 whole eggs
2 cups mashed potatoes
1 cup milk
5 tsp. baking powder
4 cups all-purpose (not bread) flour
1/2 tsp. salt
1/2 tsp. nutmeg or mace
1 tbsp. melted butter
Combine all ingredients (a food processor may be used).
Roll out on a lightly floured surface. Adjust dough consistency, if needed, adding flour if dough is too sticky or a little milk if too crumbly, until a soft, rollable dough is obtained. Add as little flour as is possible to avoid having heavy, tough, doughnuts.
Cut out doughnut shapes using a doughnut cutter, two biscuit cutters or two glasses (a shot glass is a good size for cutting out the doughnut holes). Dip the cutters in flour before each cut.
Use a spatula sprayed with non-stick spray to transfer the doughnuts to hot oil (about 370°F). Turn once until browned on both sides and cooked through. If outside of doughnut browns before inside is cooked, reduce temperature.
Remove from oil using a slotted spoon and drain on paper towels. Shake in a brown paper bag filled with granulated sugar (cinnamon may be optionally added) or dust with confectioners sugar while still warm.
For a festive look, drizzle with confectioners icing and sprinkle with colored jimmies.