Beat the egg yolks, the pulp of the vanilla pod and the sugar in a bowl over a hot water bath for 5 minutes until a frothy, creamy mixture is formed. Remove the bowl from the pan and beat the mixture again until cold.
Whip the cream until stiff and fold into the mixture.
Marinate the raspberries with powdered sugar and raspberry brandy. Put the fruits in an ovenproof dish. Spread the gratin mixture over it.
Turn the grill on to the highest setting and gratin the dessert for about 5 minutes until golden brown.