Place the double cream, coffee, milk, sugar and the vanilla pod (both seeds and split pod) in a pan. Bring to a simmer and stir thoroughly to ensure all the sugar is dissolved. Remove from the heat.
Remove the gelatine from the cold water and squeeze to remove any excess liquid. Gradually whisk the gelatine into the warm milk mixture, ensuring it is evenly incorporated.
Pour the mixture into four dariole moulds or ramekins and set in the fridge for at least two hours, preferably overnight.
When ready to serve, dip each of the moulds into hot water to loosen. Turn out onto serving plates.
For the chocolate sauce, bring the cream to a low simmer in a pan. Gradually add the chocolate, while stirring continuously, until it is all incorporated.
Serve the panacotta with the hot chocolate sauce.
