1 Put hot potatoes in mixing bowl with butter; stir until butter is melted and mixed in. Let mixture cool. Mix in eggs; sift dry ingredients together into mixture and stir until smooth. 2. On floured surface, with well-floured rolling pin, roll dough to 1/2 inch. Using floured doughnut cutter, punch out doughnuts. Gather scraps together and repeat until dough is used up. Fry a few at a time in deep fat at 360 F. Turn carefully with slotted spoon when they rise to the surface. Continue turning and frying until well browned. Drain on paper towels. Eat while still hot.