Cut the vanilla bean in half lengthwise and scrape out the seeds.
Add the cream, sugar, vanilla seeds and the vanilla bean to a saucepan.
Simmer the vanilla cream for about 8 minutes over medium heat.
Meanwhile, soak the gelatin in cold water.
Remove the vanilla bean from the cream.
Squeeze the gelatin leaves with your hands.
Add the gelatin to the hot vanilla cream and stir to dissolve.
Pour the vanilla cream into ramekins and refrigerate.
Chill 6 hours.
Puree the raspberries with a blender and press through a fine sieve.
Press again through a sieve.
Loosen the edges of the panna cotta with a knife.
Briefly dip the ramekins into hot water and turn out onto plates.
Serve with raspberry sauce.