Preheat the oven to 180 °C
Whisk the egg white with 2/3 of the icing sugar until half stiff, then add the lemon rind, cinnamon and the rest of the sugar, and keep whisking until the mass is stiff and glossy. Carefully fold in the almonds and the sifted flour. Draw 6 circles about 24 cm Ø on baking paper. Spread each of them thinly with the cake mixture. In batches, bake each one light brown in a hot ovenwith the door partially open for 8–10 minutes. Loosen the bottom of each cake from the paper with a spatula and then allow to cool. For the cream filling, beat the butter until creamy. Heat about 2/3 of the milk with the sugar and vanilla pulp. Use the rest of themilk tomix with the custard powder, egg yolks and cherry brandy. Stir until smooth, then combine with the milk mixture. Allow to cool. Spoon the cooled custard into the creamy butter mixture, and stir until it becomes a smooth butter cream.
Spread the cream over five of the cake layers and place them on top of each other, keeping some cream for the end. Put the 6th layer upside down on a bench surface. Heat the jam and rum and spread over the bottom. Warm the fondant to body temperature (no hotter than 40 °C) and pour, slightly cooled, over the layer spread with jam (6th layer), keeping about 2-3 tablespoons for the decorative pattern. Quickly smooth over with a spatula. Place this layer on top of the cake and spread the sides of the cake with the rest of the butter cream. Apply the shaved almonds to the sides of the cake. For the typical Esterházy decorative pattern, stir some cocoa into the fondant and
fill into a pastry bag. At a distance of about 2 cm, squeeze out semi circles and quickly take the back of a knife and pull it across perpendicularly from alternate sides. (See photo for pattern).
Allow to stand for a while before cutting.