Fry 4 doughnuts at a time for 3 to 4 minutes or until golden, turning them over halfway through. Watch out for splattering. Drain the doughnuts in the basket of the deep fryer for a few seconds, then quickly dip them one at a time in the icing. Let drain on the wire rack. A thin layer of icing will crystalize over the doughnuts. Repeat with the remaining dough. Fry the doughnut holes and any scraps. Although best enjoyed the same day they are made, the doughnuts will keep for 2 days in an airtight container at room temperature.