75 gr. White flour
1 pinch of salt
5 eggs
150 gr. sugar
75 gr. Potato flour
To prepare the sponge cake, divide the egg whites from the yolks putting them in two separate large bowls, start to beat with the help of electric whisk, egg yolks with half the sugar until the mixture is fluffy, puffy and light yellow.
Beat now the egg whites until glossy and after about five minutes when they are already quite swollen and white, add the remaining sugar. Continue to whisk for a few minutes. Mix together the egg whites to the yolks and mix well. At this point add the flour and potato flour sifted together, pouring the mixture through a sieve to make sure that no lumps are formed.
Mix everything with a wooden spoon until the mixture is smooth, being careful not to remove it. Grease and flour a round baking pan and pour the mixture.
Take preheat the oven to 180 degrees and bake your sponge for at least 35-40 minutes without opening the oven in the first half hour of cooking, otherwise it collapses.