340g packet chocolate cake mix
300g dark chocolate, chopped
3 cups thickened cream
¼ cup pure icing sugar
Preheat oven to 180C (160C fan forced). Spray and line a 18cm x 28cm slice pan. Prepare cake mix, spoon into the lined slice pan. Bake for 20-25 min. Cool on a wire rack. Line the pan with plastic wrap and return the cake to the pan.
Combine chocolate with 1 cup thickened cream in a saucepan, stir over a medium heat until smooth. Whip a further 1 cup thickened cream with ¼ cup icing sugar until stiff peaks form. Fold through the cooled chocolate mixture.
Spoon chocolate mousse, over cake and chill for 3-4 hr. When cake is set, whip remaining 1 cup thickened cream until stiff peaks form. Pipe cream on top of cake using a 1cm piping nozzle.
Decorate the cream with grated chocolate and chill until required. Serve cut into squares.