Gather in the bowl of the mixer the egg yolks and 60 g of sugar, then operate the machine with a whip and whip the ingredients until the mixture is light and fluffy. In another bowl pour the egg whites and mount them again with the mixer with hook whip. Gradually add the remaining sugar to the egg whites while mountain. At this point add also the vinegar always with the machine in operation. When the egg whites are well turn off machine. Combine the two mixtures: add some of the egg yolks and stir from the bottom up to mix everything without removing the mixture. Add the sifted flour a little at a time, stirring always from the bottom upwards.
Gather the dough into a pastry bag with a plain nozzle and made of strips in a baking tray lined with greaseproof paper. Sprinkle the biscuits with sugar and bake at 200 ° C until golden brown. Arrange the biscuits on a plate and serve.Ladyfingers.