Put the raisins in a small bowl with the grappa and warm water. Let them soak for 15 minutes while you mix the batter, then drain and pat them very dry with a clean towel.

In a 3 L / 3-quart mixing bowl, whisk the flour, sugar, yeast, salt, lemon zest, and orange zest. In a jug, whisk the lukewarm milk, eggs, and cooled melted butter, then pour into the dry mix. Stir with a wooden spoon until smooth and thick enough to fall from the spoon in a slow ribbon, then fold in the raisins and pine nuts.

Cover the bowl with a damp towel and leave it at room temperature, about 22 to 24 C / 72 to 75 F, for 60 minutes. The batter is ready when it has doubled and the surface is covered in bubbles.

Pour the oil into a 24 cm / 9.5-inch heavy-bottomed pot so it's about 3 cm deep, and heat it to 170 C / 340 F. Line a 33 x 46 cm / 13 x 18 inch sheet pan with paper towels. Watch the thermometer: above 180 C / 356 F the shells brown before the centers set and you end up with raw batter inside.

Stir the batter once, gently, to keep the air in. Using two lightly oiled tablespoons, drop 6 heaping spoonfuls into the oil, leaving space between them. Fry for 3 to 4 minutes, turning once or twice, until they're deep golden on all sides and the centers are set and fluffy.

Lift the fritole out with a slotted spoon and drain them on the paper towels for 2 minutes. Repeat with the remaining batter in 3 more batches of 6, letting the oil return to 170 C / 340 F between batches. Dust with powdered sugar through a sieve and serve within 30 minutes.