Knead butter with margarine and mix with mixer until fluffy. Knead raw marzipan until soft and gradually add to butter mixture with yolks. Add vanilla sugar and salt, stir until fluffy. Sift the cornflour and fold in, finally stir in the orange marmalade and fruit brandy. Beat egg whites with sugar until stiff and fold in carefully with the sifted flour. Butter a cake pan and sprinkle with sliced almonds. Pour in the mixture and bake in a preheated oven at 160 °C for about 45 minutes.