1
Put a little cold water in a bowl and soak the gelatine in it. In a bowl, mix well the rum, grated lemon zest, eggs and sugar.
2
Whip the sweet cream and add it to the mixture. Add the softened butter and the softened gelatine.
3
Add melted chocolate (melt over a water bath) to half of the cream and whisk evenly.
4
Place the sponge cake layer in a ring and moisten it with sweetened water. Place the chocolate cream on top first, followed by the ''white'' cream.
5
Place the cake in the fridge for a few hours or overnight to set. Then take it out of the ring and decorate as you like. You can also drizzle melted chocolate over the cake.