Stir the pudding powder, 50 g sugar and 5 tbsp milk until smooth. Bring the remaining milk to the boil, stir in the pudding powder, bring to the boil and simmer for 1 minute. Pour into a bowl, cover directly with foil so that no skin can form. Let cool at room temperature for about 4 hours
For the dough, whisk 50 g butter, 50 g sugar, salt and vanillin sugar with the whisk of the hand mixer until foamy. Stir in egg yolk. Mix flour and baking powder, stir in (dough is very firm). Pour the dough into a greased springform pan (18 cm Ø), smooth it down. Bake in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for approx. 18 minutes. Take out, let cool down
Roast the flaked almonds in a pan without fat, turning them several times until golden, remove them and let them cool down. Remove the base from the pan and put it back into the pan. Stir the pudding briefly. Whisk butter with the whisk of the hand mixer until thick and creamy white. Stir in the pudding by the spoonful
Spread a good 2/3 of the buttercream on the base and smooth it down. Chill for about 30 minutes. Cover the rest of the buttercream and put it aside. Sort the berries. Wash the blackberries and blueberries, drain well
Mix the cake glaze powder and 4 tbsp. sugar, stir gradually with juice until smooth, bring to the boil. Carefully fold in the fruit. Let cool for about 3 minutes. Carefully pour onto the cake. Chill for about 1 hour.
Remove the cake from the springform pan, carefully spread the remaining buttercream 2-3 cm high on the cake's edge. Decorate with flaked almonds, chill for about 1 hour
Preparation time approx. 1 hour. waiting time approx. 8 hours