Mix butter, vanillin sugar, 250 g sugar and salt with the whisk of the hand mixer in a mixing bowl for about 5 minutes. Stir in eggs and 3 tbsp. milk one after the other
Mix 400 g flour and baking powder. Add and stir in briefly. Halve the dough and put into 1 mixing bowl each. Fold vanilla pulp and 3 tbsp. milk into one half of the dough. Remove 3 tbsp. of dough from the other half and puree with the beetroot. Stir the beetroot mixture, 4 tbsp. flour and food colouring back into the remaining dough
Place the dough by the spoonful in a greased springform pan (26 cm Ø) sprinkled with flour and marble lightly with a fork. Bake in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for approx. 35 minutes. Cover if necessary. Remove the cake from the oven, let it cool in the mould for approx. 3 hours
Beat the egg white until stiff and slowly add 100 g sugar. Beat the mixture until the sugar has dissolved. Divide the cake into three parts horizontally. Spread 3 tbsp. jelly evenly on the base. Place the middle cake base on top and spread as well. Place the top cake layer on top
Spread the cake with the beaten egg white. Brown lightly with a crème-brûlée burner or brown for approx. 5 minutes under the preheated grill
waiting time approx. 3 hours