In a suitable bowl, mix the softened margarine, vanilla sugar and 150 g of powdered sugar, and then mix with a mixer.
Separately, mix the egg yolks with remaining sugar and cook on steam with constant stirring until a thick cream is obtained.
Stir the creamy yolk cream with the mixture of margarine, add the melted chocolate and mix with a mixer.
Squeeze the sour cream well and sweep the sweet sour cream in a solid whipped cream.
Put the biscuits into milk and cover with them the bottom of the appropriate cake pad. Brush with half the prepared chocolate cream, lay half of the cherry blossoms with a third of the sour cream. Repeat the same procedure and finish with biscuits.
Cover the cake with the remaining whipped cream and return it to the fridge.