Whip the Debic Parfait with the ground vanilla pods into a well aerated mousse.
Put the mousse in a piping bag and divide into verrines.
Leave to set in the freezer.
Prepare the granita by mixing the other ingredients in a bowl.
Put in the freezer and stir with a fork for 10 minutes until long ice crystals appear.
Add the coffee granita to each vanilla parfait and leave in the freezer.