Start with the fruit. Pour the apple juice into a saucepan and bring to a simmer. Add the butter, let it melt, then take off the heat and add the syrup and rum. Put the mixed fruit and cranberries into a large bowl, pour over the hot rum mix, then cover tightly with cling film and leave overnight.
The next day, heat oven to 160C/140C fan/gas 3. Grease and double-line a 20cm round, deep cake tin with non-stick baking parchment. Beat the butter and sugar together until creamy and pale, then gradually beat in the eggs until light and fluffy. If the mix starts to split or look lumpy, add 1 tbsp of the flour and keep beating. Sift in the flour, spices and 1/4 tsp salt, and fold in using a large spoon. Fold in the orange zest, nuts, soaked fruit and soaking liquid.
Spoon the batter into the tin, level the top, then make a slight dimple in the middle using the back of the spoon. Bake for 1 hr 30 mins, then reduce oven to 140C/120C fan/gas 1 and bake for a further 1 hr 45 mins or until it has risen, is a dark golden colour and a skewer inserted into the middle of the cake comes out clean. Put the tin on a cooling rack and leave until warm.
To feed the cake the first time, use a cocktail stick to poke all over the top of the warm cake. Stir together the rum and maple syrup, then slowly spoon over the cake. Cool completely, then remove the baking parchment, wrap loosely in clean baking parchment and store in an airtight tin. Feed the cake every week to 10 days until you decorate it.
Now you're ready to cover and ice your cake. Sit the cake on a large flat plate or board and brush a thin layer of apricot jam over the top and sides.
Dust the work surface with icing sugar. Lightly knead the marzipan until pliable, then roll out in one direction, turning the marzipan 90 degrees every few rolls and keeping the pressure even. Keep it in a circular shape, reshaping it if needed as you go. When large enough (about 35cm across for a 20cm cake), lift over the cake. Smooth the top and sides with your palms and trim with a knife. If you have time, leave to dry overnight.
Clean the work surface and rolling pin. Using a pastry brush, lightly brush the sides with cooled boiled water or alcohol, then cover with the sugarpaste icing, rolling it in the same way. Lift onto the cake, then work your way gradually around, smoothing out any folds with your palms to avoid wrinkles forming. Polish the icing with the palms of your hands (or a proper cake smoother) for a smooth finish. Trim with a sharp knife.
Using the cutters, cut out shapes in the icing, pressing down as far as the marzipan, then removing the middles. To make teardrop and bird shapes, use a small sharp knife to cut points above and below or to the sides of the circles.
Mix the icing sugar and egg white to make a thick but flowing icing. Split it roughly between five pots – leave one white, then colour the others. Flood each shape with a different colour, then add some coloured balls and leave to set. A pair of craft tweezers will help if you want the balls to be in a design rather than just scattered over.
Add a dab of black colouring to the remaining white icing to make it grey, and add a little more icing sugar to thicken it. Spoon into the piping bag, snip off the end, then pipe on the strings, bows and stars or snowflakes. Tie the ribbon around the base of the cake and leave to dry.