Soak the gelatine in cold water. Slit the vanilla bean, remove the pulp and pour into a large bowl. Add the rum, chestnut puree, syrup, port and cinnamon.
2. melt the dripping wet gelatine in a small saucepan and add to the chestnut puree.
Whip the whipped cream until stiff. When the chestnut puree begins to gel, stir in the whipped cream. Pour into a mold and cool for 2 hours.
4. boil the sour cherries together with their liquid and rum in a saucepan with the prunes. Thicken with the cornflour and cool.
Divide the sauce evenly among plates dusted with powdered sugar. Make dumplings from the mousse and arrange on top. Garnish with fresh mint and a little brittle.