First make the jelly. Add the boiling water to the jelly cubes and marmalade and stir until dissolved. Pour into a 20cm x 20cm square baking tin and place in the fridge to chill until set (around 1-2 hours).

Preheat the oven to 180'C. Using the butter, grease a small, 12-hole bun tin and set aside.

Add the eggs and sugar to a mixing bowl and beat with a hand-held mixer for 4-5 minutes until pale and fluffy. Then fold in the flour, xantham gum and baking powder.

Spoon approx 1 dessert spoon of the mixture into each hole, smooth with the spoon and then place the tray in the oven. Bake for 8-9 minutes. The buns are ready when they start to go golden brown and spring back when pressed gently.

Allow the buns to cool in the tray before carefully removing with a knife. Cool completely on a wire rack.

Once the jelly is set, remove from the fridge and turn out onto a piece of greaseproof paper. Using a cutter (or shot glass, like I did!) cut out small circles for each sponge base. These should have a small gap around them when placed in the centre.

Melt the chocolate and spoon over each Jaffa Cake. Spread it out evenly over the top and then very gently drag a fork along the centre to create the classic Jaffa Cake pattern. Chill in the fridge to set for 30 mins - 1 hour before eating.