Clean, wash and cut the rhubarb into pieces. For the crumbles, put 200 g flour, cinnamon, 150 g sugar, salt and 150 g fat in flakes in a bowl and work into crumbles with your hands.
For the base, beat 250 g fat, 250 g sugar, salt and vanillin sugar with the whisks of the hand mixer until foamy. Stir in the eggs one after the other. Mix 250 g flour, starch and baking powder, add and stir in.
Put the dough on a greased baking tray (32 x 39 cm), smooth it down and spread rhubarb on top. Sprinkle crumbles and flaked almonds on top. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for about 35 minutes.
Meanwhile melt 50 g butter and sprinkle the cake with it about 5 minutes before the end of the baking time. Remove the cake from the oven, place it on a cake rack and sprinkle with 25 g sugar. Let the cake cool down and cut it into pieces. Tastes delicious lukewarm.