Method

• 1.
  At least 1 hour and up to 1 day before you begin this dough, soak the raisins in the Marsala until most of the liquid is absorbed.
• 2.
  Peel potato and cut into quarters. Place in a small saucepan and cover with water; potato should be fully submerged. Bring water to the boil over high heat, then turn heat down to medium, cover pan and simmer until potato is tender, about 30 minutes. Drain potato and mash or put through a ricer, then allow to cool.
• 3.
  In a small bowl, stir together the milk, honey and yeast. Set this aside until it begins to get foamy, about 10 minutes. Transfer this mixture to a large bowl and, with a wooden spoon, stir in the cooled mashed potatoes, 1/2 tsp fine salt, lemon zest, fennel seeds and soaked raisins. Combine well. Stir in the flour, a handful at a time, until a very soft dough forms. Lift the dough with your hand and slap it back down into the bowl with some authority. Do this another 10 times, then cover the bowl and let the dough rise for about 2 hours, or until doubled in size.
• 4.
  In a heavy saucepan over medium heat, bring 10cm oil to 177°C. In the absence of a deep-fry thermometer, test the oil by inserting the handle of a wooden spoon into it. If bubbles quickly form against the handle, the oil is ready for frying.
• 5.
  Now grab 2 soup spoons. Dip both in the hot oil for a second, then scoop up a spoonful of dough with one and push it off the spoon into the oil with the other. Continue with more dough, but don’t crowd the pan. Fry frittelle until they are nicely browned all over, about 4 minutes total. They should turn over in the oil by themselves, but you may have to coax them. Remove from the oil and drain on paper towels or on a rack set over a baking tray.
• 6.
  Put the sugar in a paper bag and add a few frittelle at a time. Close bag and shake until they are coated with sugar. Serve warm.