Based on my grandmother’s recipe
Sugar, weighing as much as the eggs (approx. 400 g)
Flour, weighing as much as 6 eggs (approx. 300-330 g)
Butter, weighing as much as 3 eggs (approx. 150 g)
1 teaspoon baking powder
1 sachet of vanilla sugar
Fruit on your choice (apricots, nectarines, cherries, raspberries, strawberries, apples)
In a bowl, whisk the egg yolks, sugar and butter until smooth. Flavor with vanilla. Then, stir in the flour sifted with the baking powder. If the dough starts to get too thick, set a little flour aside.
Beat the egg whites until stiff peaks with a pinch of salt. Mix them gently into the dough. Then add the remaining flour with soft upward movements (with a wooden spatula).
Pour the mixture into a rectangular baking dish, wide and deep enough (buttered). Cut the fruit into halves or slices (if they are big), leaving the small ones as they are. Place them on the dough.
Bake the cake in the oven at 180°C until a knife comes out clean. This may take between 45 and 60 minutes. In my case, baking stretched to nearly 90 minutes, but my dish wasn’t large enough (making only 26 by 26 cm) and the dough was too thick.