Place all the dried fruit, including the cherries, into a large mixing bowl, pour over your brandy and stir in the zest. Cover with clingfilm and leave to soak for three hours.
Grease and line a 23cm/9in deep, round tin with a double layer of greased greaseproof paper and preheat your oven to 140C/120C Fan/Gas 1.
Measure your butter, sugar, eggs, treacle, almonds and pecans into a very large bowl and beat well (preferably with an electric free-standing mixer). Add the flour and ground spice and mix thoroughly until blended. Stir in your soaked fruit. Spoon into your prepared cake tin and level the surface.
Bake in the centre of your preheated oven for about 4-4½ hours, or until the cake feels firm to the touch and is a rich golden brown. Check after two hours, and if the cake is a perfect colour, cover with foil. A skewer inserted into the centre of the cake should come out clean. Leave to cool in the tin.
When cool, pierce the cake with a fine skewer and feed with extra brandy. Wrap your completely cool cake in a double layer of greaseproof paper and again in foil and store in a cool place. It will keep for up to three months.
For the covering, stand the cake upside down, flat side up, on a cake board which is 5cm/2in larger than the size of the cake. Brush the sides and the top of your cake with warm apricot jam.
Liberally dust a work surface with icing sugar and then roll out the marzipan to about 5cm/2in larger than the surface of the cake. Keep moving the marzipan as you roll, checking that it is not sticking to the work surface. Dust the work surface with more icing sugar as necessary.