This cake is probably the easiest dessert in the world to make; it simply requires good-quality chocolate. It is exceptionally dark and rich – with no added sugar. The smallest slice is all you need.
225g/71/2oz dark chocolate
250ml/8fl oz double cream
2tbsp cocoa powder
Break the chocolate into small pieces and place in a bain-marie (it is important that the base of the bowl should not touch the water, as the chocolate should steam-melt, rather than cook). Do not stir, just let the chocolate melt gently on its own. In a separate pan heat the cream, then stir into the melted chocolate.
Line a 15cm cake tin with parchment paper and pour in the chocolate and cream mixture. Allow to cool to room temperature, then place in the fridge for about an hour.
To serve, remove from the cake tin and slice with a sharp knife that has been dipped in hot water.