Grease the fat pan (approx. 32 x 39 cm) well and dust with a little flour. Cut off rhubarb leaves and ends. Wash the sticks, dab dry and cut them into 1-2 cm long pieces
For the quark cream, stir quark, cream, pudding powder, Citro-Back and 75 g sugar until smooth. For the crumbles, first knead 125 g sugar, 150 g butter in flakes and 200 g flour with the dough hooks of the hand mixer. Then crumble briefly with your hands
For the batter, whisk 200 g sugar and 200 g butter with the whisk of the hand mixer until foamy. Stir in the eggs one after the other. Mix 250 g flour and baking powder and stir in briefly. Spread the dough evenly on the fat pan
Add the quark cream and smooth it down. Spread rhubarb pieces on top. Sprinkle the crumbles over it, crushing them again if necessary. Bake the cake in the preheated oven (electric range: 200 °C/ convection oven: 175 °C/ gas: level 3) for 45-50 minutes
Let the cake cool down for about 2 hours. Dust with icing sugar and cut into about 24 pieces. Arrange on a plate. Decorate with mint. Whipped cream tastes good with it