● Add the melted white chocolate to one bowl of whipped cream and the dark chocolate mixture to the other and fold each together until they are both smooth and combined.

● To build the cake: line a rectangular baking dish approximately 30cm x 10cm with cling film.

● Arrange a quarter of the whole biscuits in a layer on the bottom of the baking dish. Break them to form a flat layer where necessary.

● On top of the biscuit layer spread half the dark chocolate cream and make it level. Top with another layer of biscuits and half of the white chocolate cream and make that level.

● Repeat this process until the biscuits and creams are used up then freeze for 4 hours until the cake is frozen.

● For the frosting: melt the dark chocolate and double cream together until smooth.

● Carefully remove the cake from the baking dish and place it upside down on a serving plate. Remove the cling film. Pour the melted chocolate evenly over the cake and put the cake back in the freezer on the plate for another half an hour.

● If you want the effect above, melt some white chocolate and drizzle it over the dark chocolate before serving.