When my children were small, I made these at least once a week. Some mornings I would take a short cut and just drop the dough by spoonfuls into the hot oil and make potato doughnut drops. Either way, they loved these. They are best eaten right after they are made. They never lasted to the next day in our house, but if you keep them till the next day, put them in a brown paper bag, sprinkled with water and heat in a 350 degree oven for about 15-20 minutes. They taste like you just cooked them.
4 1/2 cups flour
1 tsp. salt
1 tablespoon baking powder
1 tsp. baking soda
1 tsp. freshly grated nutmeg
1 cup sugar
1/8 cup oil
1 cup mashed potatoes (I would save a cup from a dinner and freeze it till I made the doughnuts)
1 cup sour milk (or add 1 tsp. vinegar to 1 cup milk)
Cinnamon sugar – 1 cup sugar, 2 tablespoons cinnamon
Mix dry ingredients. Beat eggs and sugar until light and fluffy. Add oil, potatoes, and milk. Beat till smooth. Add dry ingredients. Chill. Roll out 1/2 inch thick and cut with doughnut cutter. Fry in hot oil (about 190 degrees) until golden brown. Turn over and fry other side. Drain on paper towels and then toss with cinnamon sugar to coat both sides.