Melt the fat at low heat. Separate eggs. Beat egg yolks, icing sugar and vanillin sugar for approx. 5 minutes until very creamy. Beat egg white and salt until stiff. Sift the flour, potato flour and baking powder over the ground almonds and mix everything.
Carefully fold a part of the almond mixture into the egg yolk mixture with a pastry spatula, then fold in a part of the melted, slightly cooled fat. Alternately fold in the ingredients, carefully fold in the egg white.
Pour the dough into a greased springform pan (24 cm Ø) sprinkled with flour. Bake in the preheated oven (electric: 175 °C/ gas: level 2) for approx. 35 minutes. After baking, prick several times with a wooden skewer and soak with the almond liqueur.
Let the cake cool down on a cake rack. Roast the flaked almonds in a dry pan until golden brown. Remove the cake from the springform pan. Melt the chocolate coating in a hot water bath. Cover the cake with the chocolate coating.
Immediately sprinkle all around with the flaked almonds. Let the chocolate coating set and serve the cake. Makes about 16 pieces.