Preheat your oven to 160C / 300F / Gas mark 3 and line a 8 inch / 20 cm round tin with baking parchment and place to one side.
In a large bowl add in the sultanas, raisins, currants, dried cranberries, sour cherries and the candied mixed peel and give it all a little stir.
In a food processor add in the stoned dates, margarine, banana, clementine juice and zest and pulse until you have a fine puree.
Pour the puree into the fruit and mix it all together.
Add in the chopped walnuts and sunflower seeds and mix it all together.
Sieve in the fine polenta, rice flour, baking powder, xanthan gum and spices and mix everything together.
Pour the batter into your prepared cake pan, level off the top and pop it into the middle of your warm oven.
After 1 hour and 20 minutes check your cake to see if it is baked through by inserting a skewer into the middle of it, if it comes out clean then it is done if not give it another 5 minutes and check again. All ovens are different and this must be taken into account especially for a fruit cake.
Once the cake is baked carefully remove it from its tin and place it on a wire rack to cool down.
If you want to use dark rum sprinkle it over the top of the cake while it is still warm then leave the cake to fully cool down.
Then decorate the cake in any way you desire. I melted my jam and rolled out my marzipan to a 10 inch round then covered the cake.
I then wrapped it in baking parchment and left it for 24 hours.
I then pasted on another covering of melted jam and rolled out the white icing to a 10 inch round and covered the cake.
I took the off cuts of the white icing and rolled it into a large sausage shape and cut off the ends and made little snowballs with it to scatter atop of the cake.
I took 3 small lumps of the green icing and made them into cone shapes and took the brown icing and made little round trunks out of it. And placed them to look like trees.
I then rolled out the remaining green icing like a long sausage and twisted it with the white icing to give it the green and white ribbon around the bottom.
But like I said decorate this cake however you want too!