Step #1
Grease and line a 23cm (9 inch) round cake tin with cling film. Remove the zest from the oranges and set aside.
Step #2
Squeeze the juice from the oranges and add the sugar. Heat gently in a saucepan until the sugar has dissolved. Meanwhile soak the gelatine leave in cold water for a few minutes. Remove the gelatine leaves and squeeze out the excess water and add to the warm orange juice and stir until dissolve.
Step #3
Pour the liquid into the lined cake tin and allow to set in the fridge for at least 4 hours or overnight. Place the water, oil, orange zest and cake mix into a bowl and mix to a smooth batter, beating for 1-2 minutes.
Step #4
Pour into a greased and lined 23cm (9 inch tin) round cake tin and bake in a preheated oven 180°C (360°F, Gas Mark 5) for 40-45minutes until golden in colour and firm to the touch. Allow the cake to cool completely before decorating.
Step #5
Heat the cream in a small pan until hot but not boiling and then take off the heat. Add the chocolate, allow to stand for 5 minutes and then mix to form a smooth ganache. Allow to cool and thicken up. Remove the cake from the tin and place on a plate. Trim the top of the cake to give a flat surface.
Step #6
Warm the apricot jam in the microwave for about 1 minute until a little runny. Brush over the top of the cake and the flip the jelly out of the tin on top of the cake - trim if necessary. Swirl the cooled chocolate ganache over the jelly carefully, allowing it to run down the side.
