For the rhubarb crumble cake, first prepare the dough. For the dough, cream 250 g butter. Gradually add 150 g sugar, 1 vanilla sugar, 1 tablespoon cinnamon, rum and eggs and beat until creamy.
Mix 400 g flour with baking powder and stir into the dough alternately with the milk. Put the dough on a baking tray with baking paper and smooth it down.
Preheat the oven to 160 °C hot air. Clean the rhubarb, wash it and cut it into not too big pieces. For the crumble, knead 100 g wheat flour with 100 g butter, 50 g, sugar, vanilla sugar, cinnamon and grated almonds.
Sprinkle over the rhubarb and bake the cake in the oven for about 45 minutes.