At least 1 hour and up to a day before you begin this dough, soak the raisins in the Marsala or orange juice until most of the liquid is absorbed.

Peel the potato and cut it into quarters. Place it in a small saucepan and cover with water; the potato should be fully submerged. Bring the water to a boil, then turn the heat down, cover the pan and simmer until the potato is tender, about 30 minutes. Drain the potato quarters and mash them or put them through a ricer, then allow them to cool.

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, salt, zest, fennel seeds and soaked raisins. Combine well.

Now 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 a heavy saucepan over medium heat, bring 10 cm of 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.

Now grab two 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 the frittelle until they are nicely browned on both sides, about 4 minutes total. They should turn over in the oil by themselves, but you may have to coax them.

Remove them from the oil and drain on paper towels or on a rack set over a baking sheet.

Put the sugar in a paper lunch bag and add the frittelle a few at a time. Close the bag and shake until they are coated with sugar. Serve warm.