In a saucepan slowly bring the cream to the boil.

Turn off the heat and add the coffee and chocolate.

Stir with a whisk until the mixture becomes smooth and the chocolate has melted.

The liquid should have become slightly lighter and shinier at this stage.

Pour into a jug and leave to cool for about 2 hours or until it has come down to room temperature.

See Cook's note*.

Beat the mixture with an electric whisk for about 1 minute or until it changes color.

Line a square plastic container with baking paper and pour the chocolate mixture into it.

Leave to set in the refrigerator for 2 hours.

You can test this by pressing the top with your fingers.

Run a spatula around the edges and lift the chocolate on the baking paper out of the dish and swiftly cut it lengthways into even strips of about 2/3-inch.

Then cut these into cubes.

Put cocoa powder into a flat dish and roll the cubes in it, making sure that they are well coated.

The truffles can be kept for about 2 weeks.

*Cook'snote: Alternatively you can place it in the refrigerator for 20 minutes, giving it a stir every 10 minutes.