Preheat the oven to 185 °c. Fan.
In a bowl combine sugar and melted butter. Add the eggs and whisk for 1 min.
Add the buttermilk.
Sift and fold in the dry ingrediens.
Pour the batter into a 22 or 26 cm. Spring form with baking paper attached.
Add half of the rhubarb and raspberries on top followed by ⅓ of the streusel which you crumble on with your hands and then the other half of the fruit & lastly the remaining streusel.
Bake in the oven for 45-60 minutes. (Or till a toothpick comes out clean)
Let it cool down completely before enjoying!
