We separate the whites from the yolks in two different containers. We beat the whites with some rods at low speed. When they start to froth and while beating, add half the sugar little by little. We continue beating for about six to eight more minutes at high speed until we get a firm meringue.
Then, without the need to wash the rods, beat the yolks together with the rest of the sugar. The color will change and they will become pale, they will also increase in volume by the amount of air incorporated. We stop beating when the rods draw a line on the yolks.
We add the flour, sifted, and the whites, beaten, to the container with the yolks. We will do it alternately and in three parts, integrating the flour or the egg whites with enveloping movements and a lot of softness. We do not add the next ingredient until the previous one is well incorporated.
We cover the base of a mold with a diameter of 18 cm and high walls with a disk of greaseproof paper. We pour the dough inside and smooth the surface. We put in the oven, preheated to 160º C with heat up and down, and cook for 35-40 minutes or until we see that it is well cooked.
The cooking time will depend on the oven of each one, as well as the temperature that can oscillate 10º C up or down. Once the cake is removed from the oven, we let it temper before unmolding. We can sprinkle with icing sugar at the time of serving, optional.