1. Cream the butter and sugar together until pale and fluffy. Gradually beat in the eggs until well incorporated and then sift in the flour, salt and mixed spice (if using) a little at a time.
2. Next add the mixed dried fruit, peel and grated lemon zest and stir into the mixture.
3. Put half the mixture into a greased and lined 18cm/7in cake tin. Smooth the top and cover with the circle of marzipan. Add the rest of the cake mixture and smooth the top leaving a slight dip in the centre to allow for the cake to rise.
4. Bake in the preheated oven for 1¾ hours. Test by inserting a skewer in the middle - if it comes out clean, it is ready. Once baked, remove from the oven and set aside to cool on a wire rack.
5. Brush the top of the cooled cake with the apricot jam. Divide the remainder of the almond paste in half; roll out a circle to cover the top of the cake with one half and form 11 small balls with the other half.
6. Place the circle of paste on the jam glaze and set the balls round the edge. Brush the cake topping with a little beaten egg.
7. Preheat the grill to high. Place the cake onto a baking tray and grill for 1-2 minutes, or until the top of the marzipan begins to brown. Alternatively, lightly heat the cake topping using a cook's blow torch, until the marzipan is golden-brown.