Put the sugar and 6 tablespoons of water in a small saucepan and heat gently
stirring
until the sugar has dissolved. Boil for a few seconds until it becomes a thin syrup.
Set the food processor running and pour the hot syrup through the funnel on to the chocolate so it melts. Add a little boiling water if some unmelted chocolate remains. Add the egg yolks and process for a few seconds before adding the Irish cream liqueur.
In a separate bowl
whip the cream until soft peaks form
then fold in the chocolate mixture. Reserve 3 tablespoons of mousse in a small bowl. Spoon the remaining mousse into small glasses or pots. Leave in the fridge to set for 6 hours or overnight.
To make the chocolate truffles
add the crushed biscuits to the reserved mousse with a splash of Irish cream liqueur. Mix well and shape into six truffle-size balls. Put on a plate in the fridge for 30 minutes.
Melt the white chocolate in a small heatproof bowl over a pan of gently simmering water
making sure the bowl doesn't touch the water. Insert a cocktail stick into the balls
dip into the melted white chocolate and swirl around until coated. Put on a piece of baking paper
and place in the fridge for 30 minutes
or until firm.
Place one truffle on top of each mousse before serving and dust with cocoa. Serve straight from the fridge.
