1. Heat your oven to 150°C. Line the base and sides of a 23cm round deep cake tin with a double thickness of baking parchment, cutting it so that it stands a good 5cm proud of the top of the tin.
2. Sift the flour, salt, baking powder and allspice together into a bowl and set aside.
3. In a large bowl, beat the butter until light and fluffy. Add the sugar and beat for several minutes until smooth and light. Beat in the eggs, one at a time, adding 1 tbsp of the flour mix with each to prevent the mixture curdling. Beat in the orange and lemon zest, vanilla extract, almond extract and brandy.
4. Using a large metal spoon, fold in the remaining flour mix, the nuts, glacé fruit, peel and angelica, until thoroughly combined. Spoon into the prepared cake tin and smooth the surface.
5. Bake for 2 ¼ – 2¾, until a skewer inserted into the centre of the cake comes out clean. Leave the cake to cool in the tin for 10 minutes, then transfer to a wire rack to cool completely.
6. When your cake is completely cold, warm the apricot jam with a splash of water, sieve and then brush it all over the cake.
7. Roll out 300g of the marzipan to a large circle, about 4mm thick. Using the cake tin as a guide, cut a round of marzipan to fit the top of the cake and position it. Roll out the other 200g marzipan with the trimmings and cut 2 long strips to fit around the side of the cake. Position these, then smooth the marzipan and mould the edges together.
8. To make the icing, beat the butter until smooth and creamy. Beat in half of the icing sugar and stir in the brandy. Beat in the rest of the icing sugar until smooth. Spread the icing evenly over the cake.