Grate potatoes and onions, using grating disk of a food processor or large holes of a grater. Transfer to a colander. Squeeze mixture to press out as much liquid as possible. Transfer to a bowl. Add egg salt pepper, flour and baking powder. Heat ½ cup oil in a deep 9 to 11 inch skillet. For each potato, drop about 2 tablespoons of potato mixture into pan. Flatten with back of a spoon so each cake is about 2½ to 3 inches in diameter. Fry over medium heat about 4-5 minutes on each side, or until golden brown and crisp. Turn over carefully so oil doesn’t splatter. Drain on paper towels. Stir batter before frying each new batch. Add more oil to pan if necessary. Serve pancakes hot, accompanied by applesauce, source cream, yogurt or cinnamon, mixed with sugar.