Wash, clean and quarter the strawberries. Clean, wash and cut the rhubarb into pieces. Grease a fat pan (deep baking tray; approx. 32 x 39 cm) and dust with flour. Mix grated coconut and 175 g sugar.
Mix with sour cream.
Preheat oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see manufacturer). Cream 400 g butter, 400 g sugar, vanilla sugar and 1 pinch of salt with the whisks of the mixer. Stir in eggs one after the other.
Mix 500 g flour and baking powder, stir in briefly.
Put the dough into the fat pan and smooth it down. Stir jam until smooth and mix with the fruit. Spread evenly on the dough. Spread the coconut shells in patches on top. Bake in the hot oven on the lower shelf for about 1 hour.
Remove and let it cool down on a cake rack.