Chop the chocolate very finely and put
it into a large bowl that will fit over a pan
of simmering water. Mix the cocoa,
coffee and vanilla with 2 tbsp cold water,
and pour over the chocolate. Place the
bowl over the gently simmering water,
give it all a stir, then remove from the
heat. Leave with the bowl of chocolate
still over the water, stirring occasionally
to check when melted.
Stir the melted chocolate, it will be
quite thick. Stir in 2 tbsp boiling water
and the chocolate will immediately thin
down and become silky smooth. Leave
to cool slightly.
Whisk the egg whites to fairly soft
peaks, then whisk in the sugar until thick
and glossy. Beat the yogurt into the
cooled chocolate. Fold about one-third
of the egg whites into the chocolate mix
using a large metal spoon, then very
gently fold in the rest of the whites until
they are evenly mixed in – being careful
not to over-mix or you will lose the
volume of the mousse. Spoon into 4 small cups or (125-150ml) ramekins and
chill for a couple of hours, or overnight.
Place each mousse on a saucer or
small plate. Top with a few raspberries,
then dust with a little cocoa powder.
Will keep for up to 2 days in the fridge.