Preheat the oven to 180°C fan and grease a 24–26cm baking dish with butter.
Beat the softened butter, sugar and vanilla sugar until light and creamy. Add the eggs and mix well.
Add the yoghurt, flour and baking powder and mix until you have a smooth batter.
Slice the nectarines or peaches and gently fold them into the batter together with the raspberries.
Transfer the mixture into the prepared baking dish and spread evenly.
Sprinkle 2–3 tbsp of brown sugar over the top.
Bake for 45–50 minutes until beautifully golden. Check with a skewer — if it comes out wet, cover the cake and bake for another 10 minutes.
Let it cool slightly before slicing and enjoy!
