In a bowl whip the butter at room temperature with half the icing sugar, when very soft, add the vanilla seeds and egg yolks one at a time. Leave aside.

In a second bowl, whip the egg whites with the other half of the sugar and a pinch of salt. Leave aside. In a further bowl, sift all the powders and add the finely chopped chocolate.

Take the bowl with the whipped egg whites and transfer half of the mixture into the bowl with the flours and the other half into the one with the whipped butter. Gently mix both compounds with a spatula. At this point, combine the two compounds and continue to incorporate without removing the egg whites.

Transfer the mixture to a 22 cm baking pan, greased and sprinkled with the potato starch.

Smart Cooking automatic cooking option

Place the dish on the third shelf of the oven. Select the Special diets> Caprese cake program

Combined steam cooking option - combined microwave - traditional

Place the pan on the third shelf of the oven and bake in Fan-assisted mode at 180 ° C for 40 min.