Very Dark Chocolate Squares
Line a 7 x 13cm (2 ¾ x 5 ¼ inch) rectangular tin, with cling film – a 450g (1lb) loaf tin is also suitable. Break the Chocolate into pieces and place in a heatproof bowl. Sit the bowl over a saucepan of barely simmering water and leave to melt. Remove from the water, stir well and cool for 10 minutes.
Put the softened butter in a bowl and sift the icing sugar on top. Carefully mix together then beat until smooth. Stir in the cream.
Using a spatula, scrape the melted Chocolate on top and mix into the buttery ingredients, then spoon into the prepared tin. Smooth the top and chill for 2 hours until firm.
Gently pull the set chocolate slab from the tin using the cling film and place on a board lined with baking parchment. Discard the cling film. Using a large, sharp bladed knife, cut the chocolate slab lengthways into 3 equal slices, and then cut each slice into 5 chunks. Put the pieces back in the fridge until required.
To decorate, break the Chocolate into pieces and place in a heatproof bowl. Add the butter and 20ml (4 tsp) water. Sit the bowl over a saucepan of barely simmering water and leave to melt. Remove from the water, stir well and set aside for about 15 minutes to cool to a thick, coating ganache.
When the ganache starts to thicken, remove the chocolate pieces from the fridge. Working on one piece at a time, spoon over a little ganache and carefully spread round the sides, tapping the board on the work surface to smooth the ganache. If the ganache starts to thicken too much, put the bowl back over hot water to melt a little.
Leave the ganache-covered chocolate pieces in a cool place to set and then serve. Prolonged refrigeration of these squares will dull the glossy finish, but if the temperature is quite warm, chill the pieces in the fridge for 10 minutes before serving.