Place 550 g flour and 1 pinch of salt in a large mixing bowl. Stir yeast and 1 tablespoon sugar until liquid. Add 75 g sugar and liquid yeast to the flour. Melt 75 g butter and add milk. Add lukewarm fat-milk mixture and egg to the flour. Mix to a smooth dough with the dough hooks of the hand mixer.
Cover and leave to rise in a warm place for about 45 minutes. For the crumbles, dice 175 g butter. Finely dice the ginger. Mix 250 g flour, 200 g sugar, 1 sachet vanilla sugar, butter and ginger with your hands to form crumbles. Knead the yeast dough again well with floured hands. Place on a greased, floured fat pan of the oven (32 x 39 cm) and roll out. Let it rise again in a warm place for about 20 minutes. In the meantime clean, wash and cut the rhubarb into pieces. Wash, clean and halve the strawberries. Sprinkle the yeast dough with coconut flakes. Spread rhubarb and strawberries evenly on the cake. Sprinkle with crumbles and bake in the preheated oven (electric range: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 25 minutes.
Let it rise again in a warm place for about 20 minutes. In the meantime clean, wash and cut the rhubarb into pieces. Wash, clean and halve the strawberries. Sprinkle the yeast dough with coconut flakes. Spread rhubarb and strawberries evenly on the cake. Sprinkle with crumbles and bake in the preheated oven (electric range: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 25 minutes. Remove from the oven, place on a cake rack and allow to cool. Cut the cake into strips and arrange on a plate
waiting time approx. 2 hours