The night before you want to make your cake... mix the raisins, sultanas, currants, peel and rum in a bowl then leave overnight to soak.
Line a 20cm round deep cake tin with a double thickness of greasproof.
Preheat your oven to 150°C / Fan 130°C / Gas Mark 2.
Beat the butter with the lemon and orange rinds until soft and pale, then gradually beat in the sugar until well mixed.
Add the lemon and orange juice then beat in the eggs a little at a time. Once you have beaten the eggs, add one tbsp of black treacle and mix.
Sift the flour and spice together then fold half the mixture into the creamed mix. Stir in all the almonds then gently fold in the remaining fruit, followed by the flour.
Spoon into tin then bake for 2½ to 3 hours, or until a fine skewer inserted to the centre comes out clean.
Leave to cool in the tin for 1 hour then transfer to a wire rack. When completely cool, wrap tightly in greaseproof paper and foil then store in a cool, dry place for at least a week.
Brush the top of the cake with jam, roll out the marzipan to fit the top of the cake then leave to dry out for 2 days.
Roll out the icing and cover the marzipan, decorate as required then you’re all set for Christmas!