Heat oil in cast iron skillet, deep fryer, or dutch oven to 350?F. Working with 3 to 4 at a time, drop doughnuts into the oil and fry on one side until golden brown. Turn over and fry the other side until golden brown. Using tongs, remove the fried doughnuts and drain on paper towels. Let cool completely, then sprinkle with powdered sugar or desired icing. You may also cut them in half and fill with your choice of custard
or fruit preserves before topping with the powdered sugar.