How to make
The whites and yolks are separated.
Beat the egg whites well with a pinch of salt. 1/3 of the sugar is gradually added to them.
The remaining sugar and egg yolks are beaten until a light yellow cream is obtained.
Carefully add the whites to the yolks with a spatula, then flour, cocoa, whites again, and so on several times.
Pour the mixture into a cake tin with a diameter of 9″ (22 cm), necessarily onto baking paper.
The cake tin is baked at 340°F (170°C) and during the first fifteen minutes the oven is not opened so that the sponge cake layer does not flatten.
It is baked (about 25 minutes) until it acquires a nice color and you can sense a pleasant aroma.
Do not pierce it with a stick because it will flatten.
We check if it is baked by pressing lightly with our fingers to check if it is soft and springy.
When we turn off the oven, we leave the sponge cake layer inside for another five minutes, then cool it on a wire rack.
Cut the cooled sponge cake layer into several thin slices.
