Boil the potatoes and mash them. Mix all the ingredients and let the mix levitate for 1 hour in a warm part of the house. Take a chunk of dough, roll it on a wood board to form a stick, unite the two end to form a Tarallo or a doughnut. Make sure the hole at the center is not small otherwise it will close when you fry them. Make all your Ciambelline and let them rest for 30 mins. Fry all the Ciambelline and as soon as they come out of the oil sprinkle them with sugar.