Tip the sugar, butter, dried fruit, whole cherries, ginger, orange zest and juice into a large pan. Pour over the rum, brandy or juice, then put on the heat and slowly bring to the boil, stirring frequently to melt the butter. Reduce the heat and bubble gently, uncovered for 10 mins, stirring every now and again to make sure the mixture doesn’t catch on the bottom of the pan. Set aside for 30 mins to cool.
Stir the nuts, eggs and ground almonds into the fruit, then sift in the flour, baking powder and spices. Stir everything together gently but thoroughly. Your batter is ready.
Heat oven to 150C/130C fan/gas 2. Butter and line the base and sides of a 18cm square tin with baking paper. Spoon the cake mix into the tin and level the top with a spoon dipped into boiling water. Bake for 45 mins, then turn oven down to 140C/120C fan/gas 1 and cook for 1 hr more or until a skewer inserted comes out clean. Cool on a wire rack. Will keep well-wrapped in foil for 2 months or freeze for 1 year.
Carefully cut the square cake in half and trim the edges so that you see the texture of the cake on all sides. Roll out each piece of marzipan on a surface dusted with icing sugar until the size of the top of each cake.
Generously brush the top of the cakes with jam, place jam-side down on top of the marzipan, then trim away the excess marzipan with a sharp knife.
Make up the fondant icing to a spreading consistency, then spread on top of the cakes so that it slightly runs over the edges. Top with cherries and holly, then leave to set. Will keep in a plastic container in a cool place for 4-7 days.