For the chocolate icing, heat the chocolate and cream in a saucepan over a low heat until the chocolate melts. Remove the pan from the heat and whisk the mixture until smooth, glossy and thickened. Set aside to cool for 1–2 hours, or until thick enough to spread over the cake.
To assemble the cake, run a round-bladed knife around the inside of the cake tins to loosen the cakes. Carefully remove the cakes from the tins.
Spread a little chocolate icing over the top of one of the chocolate cakes, then carefully top with the other cake.
Transfer the cake to a serving plate and ice the cake all over with the chocolate icing, using a palette knife
