Savoiardi

Method

1. Heat the oven to 180C (static). Line a baking tray with baking paper and fit a piping bag with a 1 cm plain nozzle. Sift 50 g of plain flour together with 10 g of potato starch and set aside.
2. Separate 2 eggs, putting the whites in a spotlessly clean bowl. Beat the yolks with 30 g of the caster sugar and 0.5 tsp of grated lemon zest for about 5 minutes, until pale, thick and falling from the whisk in a ribbon.
3. Whisk the whites with 1 pinch of fine salt on medium speed to soft peaks, then rain in the remaining 30 g of caster sugar a spoonful at a time and whisk 2-3 minutes more to a firm, glossy meringue that holds a straight peak on the whisk.
4. Fold a third of the meringue into the yolk base with a large spatula to loosen it, then add the rest in two goes, alternating with the sifted flour and starch and sifting it over the surface. Cut down and lift from the bottom of the bowl; stop as soon as no streaks remain, so the batter stays thick enough to hold a piped line.