Bizcochuelo

Preheat oven to 350°F (175°C) and grease a round or rectangular baking pan, ensuring all surfaces are well coated.

Separate the egg whites from the yolks into two clean bowls.

Beat the egg whites on high speed until stiff peaks form, approximately 3-5 minutes, then set aside.

In the same bowl or a separate one, beat the egg yolks with white sugar until the mixture is pale, fluffy, and doubles in volume, about 3-5 minutes.

Gently fold the stiff egg whites into the yolk mixture in two additions, using a rubber spatula and making broad, careful motions to preserve the airiness.

Sift the self-rising flour and powdered chocolate together over the egg mixture, then fold gently until just combined with no visible flour streaks.

Fold in the small portion of cream until the batter is smooth and uniform, being careful not to deflate the mixture.

Pour the batter into the prepared pan and smooth the top gently with a spatula.

Bake in the preheated oven for 30-35 minutes, until a toothpick inserted in the center comes out clean or with just a few moist crumbs.

Remove from the oven and let cool in the pan for 5-10 minutes, then turn out onto a wire rack if desired, or serve directly from the pan.