Stir pudding powder into 4 tablespoons of milk until smooth. Bring the rest of the milk to the boil, stir in the custard powder and bring to the boil, allow to cool in a bowl. Roast the flaked almonds in a pan without fat until golden brown.
Place a springform pan rim (24 cm Ø) on a smooth cake plate. Place a layer of sponge finger on the base and sprinkle with 3-4 tablespoons of rum. Stir the cold pudding once vigorously. Stir butter and icing sugar until creamy white. Stir in the pudding by the spoonful. Finally add ground almonds.
Spread a thin layer of butter cream on the soaked lady fingers. Place a new layer of lady fingers on top, sprinkle them again with rum and spread a thin layer of butter cream on top. Repeat this once again. Put the Malakoff cake in a cool place for about 1 hour.
Leave the rest of the buttercream to stand at room temperature. Remove the cake from the edge with a sharp knife. Spread the cream all around and sprinkle with flaked almonds. Whip the cream until stiff and fill into a piping bag with a large star-shaped spout. Spray 16 small tuffs onto the cake. Decorate with chocolate decorating leaves. Keep cool until serving