Preheat your oven to 140°C (fan 120°C), gas mark 1.
Use a little extra butter to grease the inside of a 20cm round deep-sided cake tin. Line the base and sides of the tin with a double layer of baking parchment. Make a "lid" out of another double layer of baking parchment by cutting a circle slightly larger than the diameter of the tin, snip around the edges to allow it to sit inside the lined tin. Cut a 20p sized hole in the center to allow steam to escape.
Cream the butter and soft brown sugar together until light and fluffy.
Beat in the eggs, one at a time.
Gently fold the mixed fruit, glace cherries and the orange zest into the mix.
Sift the flour and mixed spice together then fold into the mix along with the ground almonds.
Spoon the mixture into the prepared tin, smooth the surface level and cover with the baking parchment "lid". Do not let the baking parchment lid touch the surface of the cake mixture. For a little extra protection during baking, you can wrap the cake tin with a double layer of brown paper or newspaper secured with cook's string but this is not essential.
Bake on the bottom shelf of the preheated oven for 2½ -3 hours. To test if the cake is fully cooked, insert a skewer into the center of the cake, the skewer should come out clean. If not, return the cake to the oven to continue cooking until the skewer is removed clean.
Leave to cool in the tin. Then remove from the tin, peel off the baking parchment and store in an airtight container until ready to decorate.
TO DECORATE THE CAKE - For a completely flat surface, turn the cake over and decorate the base. You may have to cut the top of the cake level to allow it to sit flat on a cake board or decorative plate.
MARZIPAN LAYER - On a surface dusted with half of the icing sugar, form the marzipan into a ball and roll out into a 42cm circle, approximately 4mm thick.
Stir the jam or marmalade until smooth and then brush evenly over the top of the cake.
Use your rolling pin to lift the marzipan and place it on top of the cake. Gently smooth it into place, across the top and down the sides of the cake.
Carefully trim away any excess marzipan with a knife, to leave a neat edge around the base of the cake.
READY TO ROLL ICING - On a surface dusted with the remaining icing sugar, form the icing into a ball and roll out into a 42cm circle, approximately 4mm thick.
Brush a little water evenly over the marzipan.
Use your rolling pin to lift the icing and place it on top of the cake. Gently smooth it into place, across the top and down the sides of the cake.
Carefully trim away any excess icing with a knife, to leave a neat edge around the base of the cake.
Finish the cake with your favourite decoration and store in an airtight container until required.