Extra time:2hr ›
- In a small heavy saucepan, melt chocolate with water over low heat; stir until smooth. Stir a small amount of hot chocolate mixture into egg yolk; return all to the pan, stirring constantly. Cook and stir for 2 minutes or until slightly thickened. Remove from the heat; stir in vanilla. Cool, stirring several times.
- In a mixing bowl, beat whipping cream until it begins to thicken. Add sugar; beat until soft peaks form. Fold in cooled chocolate mixture. Cover and refrigerate the chocolate mousse for at least 2 hours.
If you want to experiment, you can try adding other flavours instead of vanilla; a nice substitute is Grand Marnier for a orange flavoured chocolate mousse. If you want an Irish cream chocolate mouse, use a bit of Baileys. I've also added a pinch of cinnamon whilst the chocolate is melting, which adds a nice, warm flavour to the chocolate mousse without making it 'cinnamon-y'.