Apple and Lemonade Cake

Prepare a 23 cm diameter cake pan: grease it well with butter and dust it with a little flour. Preheat the oven to 170°C (fan-assisted).

Sift the flour together with the baking powder. Separate the egg yolks from the whites. Beat the egg whites until stiff peaks form, along with a pinch of salt. In a separate bowl, mix the soft butter with brown sugar and vanilla sugar until it becomes a frothy cream. Add the egg yolks and continue mixing until the mixture becomes light in color and dense.

Gradually incorporate the flour and apple lemonade into the egg yolk mixture. Finally, add the beaten egg whites, mixing very gently, with upward movements, to keep air in the dough. Spread the dough evenly in the prepared pan and level the surface.