Pour the flour into a bowl and press a depression into it. Heat 100 ml milk. Dissolve yeast in the milk. Pour yeast milk and 25 g sugar into the hollow and mix with some flour from the rim to a thick paste. Cover the dough and let it rise in a warm place for about 15 minutes. Warm 150 ml milk lukewarm. Add butter, egg, 50 g sugar, salt and milk and knead well with the dough hooks of the hand mixer. Cover the dough and let it rise again for about 30 minutes. Wash and clean the rhubarb and cut it into pieces about 1 cm wide. Marinate rhubarb with 2 tablespoons of sugar and vanilla sugar. Knead the dough lightly on a floured work surface and roll out (approx. 32 x 37 cm). Put the dough on a greased and floured fat pan and let it rise again for about 20 minutes in a warm place. Spread the rhubarb and a little juice on the cake and press in lightly. Bake the cake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for 20-25 minutes. Coarsely grate the marzipan. Beat egg white and lemon juice until stiff. Add 150 g sugar and almonds and stir in. Add marzipan and stir in with the whisk of the hand mixer. Pour the macaroon mixture into a piping bag with star-shaped spout and spray a grid on the cake approx. 10 minutes before the end of the baking time and finish baking
Remove the cake, let it cool down and cut it into pieces. Whipped cream tastes good with it
Waiting time approx. 1 hour