Boil the potato in salted water until it is tender when pierced with a knife.  Drain the water and allow the potato to cool slightly then peel off the skin.  While the potato is still warm put it through a ricer and spread the riced potato on a plate to cool completely.

Put the milk in a small saucepan over medium heat and bring almost to the boil. Remove the pan from the heat, add the saffron and allow it to infuse and colour the milk, whisking occasionally until the milk has cooled to lukewarm.  Add the yeast and whisk the milk until it's completely dissolved, then allow the mixture to prove for five minutes.

Place the flour in a large bowl and combine it with the salt. In a medium bowl, whisk the egg together with the sugar, orange juice, zest, potato and grappa, along with the warm milk and yeast mixture. A dd this mixture to the flour. Work the ingredients together with a fork, then by hand, forming a ball of dough. Transfer the dough to a lightly floured board and knead it, adding more flour if necessary, until the dough is smooth and elastic, about two minutes.

Place the dough in a greased bowl, turn it once to coat it, and cover the bowl with plastic wrap or a damp towel. Place the bowl in a warm place to rise until the dough has doubled in volume, about two hours. Meanwhile, combine the caster sugar

In a heavy bottomed stockpot or deep fryer, heat the oil to 180C. Using your fingers, break off 3cm pieces of dough, and roll them into balls with your palms. Fry the doughnuts in batches three or four at a time, until they are golden brown and crisp, turning them to brown evenly.

Drain the doughnuts on paper towel, then toss in caster sugar before serving.

Makes 25-30 zippulas

You can also find other of recipes from Travel & leisure magazine, on http://www.travelandleisure.com.au