250g marmalade (you could use our Jaffa Orange marmalade recipe)
1 free-range egg
50g white caster sugar
65g self-raising flour
Butter, for greasing
100g dark chocolate (70% cocoa)
2 tsp vegetable oil (optional)
Preheat the oven to 200°C
Whisk together the egg and sugar for 4-5 minutes or until thick and creamy. Sift in the flour and fold in to the mixture.
Grease a 12-hole shallow bun tin and put 1 tablespoon of mixture in each hole. Bake in the oven for 10 minutes, or until well risen and the top of the sponges spring back when lightly pressed. When cooled slightly, transfer to a wire rack to cool. Once completely cool, cut the cakes in half horizontally, so you have 2 thin cakes.
Gently heat the marmalade in a saucepan for a few minutes, until it has thickened but is still spreadable. Sift to remove any peel, if you want a smooth centre. Spoon a dollop of marmalade onto the centre of each cake.
Roughly chop the chocolate and melt with the oil (if using) and 1 tablespoon of water in a heatproof bowl over a pan of boiling water. Grate in the Jaffa orange zest, stirring well. Cool until the chocolate starts to thicken
Spoon over the marmalade-topped cakes. Using the tips of a fork or a skewer, lightly press to create a criss-cross pattern on top of the chocolate, then leave to set completely. You may need to reheat the chocolate a little if it starts to set before you have finished all the Jaffa cakes. Leave to set before serving.
