Pour boiling water over tea leaves and infuse for 10 mins.
(I use 1 teabag).
Strain, add 2 tbsp of the Armagnac and pour over the prunes.
Cool and refrigerate for a few hours.
Strain the liquid into a saucepan, add caster sugar and bring to the boil, stirring. Allow to bubble until the liquid is reduced to a light syrup, then cool.
The prunes, syrup and cream should all be well-chilled before serving.
Beat the cream until thick and stir in remaining Armagnac and icing sugar.