Separate the yolks from the whites. Put the first ones aside and, with the help of an electric stand mixer or an electric hand whisk, whisk the egg whites for a few minutes at maximum speed. When the whites start to get stiff, add the sugar. Keep to beat the egg whites until you get a very firm, shiny and hard meringue.

Beat the egg yolks with a fork and add them to the whipped egg whites, stirring with a spatula, moving from the bottom upwards.

Add the sifted flour and potato starch, together with the lemon peel or other flavoring of your choice (optional), and mix until you get a homogeneous mixture.

Place the mixture in a pastry bag with a smooth and wide tip, and form sticks of about 10/12 cm (about ⅘ inch) on a baking sheet covered with parchment paper. During cooking the ladyfingers will expand and swell a little, so it’s important that they are spaced apart on the baking sheet. Sprinkle Savoiardi ladyfingers first with the granulated sugar and then with the icing sugar.

Bake at 200 °C (390 F) for 7 minutes. Open to let the steam out and cook for another 2 minutes. Let them cool well before using your homemade Ladyfingers for your recipes.