Melt the chocolate in a bowl over a saucepan of hot water.

In a cup mix the cocoa powder, coffee powder, vanilla essence and two tablespoons of water.

Add the mixture to the melted chocolate and stir.

Turn off the hob but leave the bowl of chocolate over the saucepan of water.

Stir in another 2-3 tablespoons of water to thin out the mixture. It should be silky.

Leave it to cool a little bit.

In a separate bowl, whisk the egg whites until soft peaks are formed.

Whisk in the sugar until thick and glossy and then whisk in the sweetener.

Stir the yogurt into the chocolate mixture.

Fold the egg whites into the chocolate with a spatula. Only put 1/3 of the eggs in at a time.

Do not over mix as it will lose it's volume.

Spoon mixture into four glasses/ramekins and allow to chill for at least four hours.

Serve with a dusting of cocoa powder/icing sugar and fresh raspberries.