How to cook
Wash the apricots and cut them in half.
Separate the egg whites from the yolks. Beat the whites with a pinch of salt at the lowest setting on the mixer. Once you get a nice foam, gradually add the sugar (you can mix white and brown sugar or just use brown instead) and turn the mixer to a higher setting.
Once the mixture becomes stable enough (the whites keep their shape), add the yolks 1 by 1, while only adding each subsequent one after the previous has been fully absorbed by the mixture. Next comes the oil, pour it in gradually.
Once you've added the oil, you don't need the mixer anymore. Combine the flour with the vanilla and baking powder and add it in 2-3 lots, sifting it into the mixture. Stir slowly and carefully with a spoon, starting from the middle at the bottom and going up and out in a circle.
As soon as the flour is absorbed, pour the mixture into a rectangular oven dish laid out with baking paper (mine was 12 1/2″ (32 cm) x 9 1/2″ (24 cm)), arrange the apricots evenly upright, not facing down, press them carefully almost to the bottom and bake in a preheated 338°F (170 °C) oven for about 1 hour.
Keep an eye on it during baking. If needed, cover the cake with foil 10-15 min. after you've put it in the oven. The dough is fine and can burn quickly on top. It's recommended to use a fan.
Check to see if it's ready with a toothpick. Take it out of the oven, let it cool, remove the baking paper. Sprinkle the ready cake with powdered sugar.