ca. 750gapples (on the sour side but still sweet)e.g. Jonathan/Topaz/Reinette
Whisk the butter (room temperature) with the sugar, vanilla sugar and chickpea brine until bright and a little foamy. Don't worry if it's not very homogenous - the flour will fix it all.
Add the flour, salt and baking powder and mix until well combined and nice and creamy.
Peel the apples, cut them in halves and take out the core. Then laying the halves on their cut side, make parallel cuts at about 2 millimeters distance that don't go all the way through the apple so it still holds together.
Preheat the oven to 180°. Line the floor of a 22 (centimeter diameter) cake pan with baking paper and pour in the cake batter. Then push the apples halves deep into the dough so the dough rises on the sides of it.
Bake the cake for 35 minutes or until a toothpick comes out dry when inserted. (Don't insert the toothpick right next to an apple because there it should stay moist :))
Let it cool a little and dust with powdered sugar. If you serve it when it's still a tiny bit warm it's extra good.
I usually take the chickpea brine from cans where the ingredients are only chickpeas, water and salt just to be on the safe side healthwise :)