Preheat the oven to 140ºC / 275ºF / Gas Mark 1. Brush a 25cm (10 inch) round cake tin or a 23cm (9 inch) square cake tin with melted Stork® and fully line with a double thickness of non-stick baking paper.
(If your oven tends to run hot, tie a single thickness of brown paper around the outside of the tin.)
Place all the fruit, almonds and zests in a bowl. Pour in the alcohol, mix well, then cover and leave overnight.
The next day, place all the remaining ingredients in a very large bowl, add the soaked fruit and beat until thoroughly mixed (3–4 minutes).
Place this mixture in the prepared tin, smooth the top with the back of a wet tablespoon and bake for 5–6 hours. Check at intervals after 3 hours as ovens tend to vary.
Cover the cake with doubled non-stick baking paper or foil for about the last 1–2 hours to prevent the top becoming too brown.
When the centre top of the cake feels firm when pressed with your fingers, insert a clean, warm skewer and if it comes out clean, the cake is ready.
At this stage there should be no sizzling noise coming from the cake. Set aside to cool in the tin overnight, then turn out and peel off the paper.
To decorate, brush the top of the cake with the apricot jam. Dust a work surface with icing sugar and roll the marzipan into a circle that sits neatly on top of the cake.
Roll the icing into a circle about 12cm (5 inches) larger than the cake. Using a knife, cut around the edge to create a wavy line. Drape the icing over the cake and press it onto the marzipan.
Using a paintbrush, dot the edible glue at regular intervals around the top of the cake, then press a silver ball onto each dot. Arrange the holly and more silver balls in the centre.
Note: The cake will keep for up to 2 months in an airtight container.