Set a pan with the cream, coffee and seeds from the vanilla pod over a medium heat. Warm through, but do not allow to boil.
Remove from the heat and leave to infuse for 30 minutes, then pass through a sieve (discarding the coffee beans).
Put the chocolate in a large heatproof bowl. Return the cream to the pan and set over a medium heat, until just simmering. Pour onto the chocolate and stir until melted. 4 Working quickly, in another bowl, whisk together the egg yolks and sugar, until pale and thick. Add to the warm chocolate cream.
Return to the pan and set over a low heat. Cook for 3-5 minutes, stirring continuously, until very thick. Pour into two small pots. Cool to room temperature, then chill in the fridge overnight.
Scatter the extra sugar on top of the brûlées. Sprinkle over ½ tsp water and caramelise with a blowtorch or under a hot grill, until golden and crunchy.