Put the granulated sugar into a saucepan large enough to hold the peaches. Add the water and the vanilla pod and bring to the boil, gently to begin with, stirring until the sugar dissolves. When simmering put in the peaches. Bring back to simmering point and very gently poach for 8 minutes. Remove the peaches and peel while still warm. The syrup can be bottled and used to poach other fruits. Put the peaches in a beautiful glass dish and chill.
Liquidise the raspberries with the caster sugar and pass through a sieve if you wish to get rid of the pips. When ready to eat, pour the red puree over the succulent peaches. Decorate with mint leaves dragged through icing (confectioners') sugar.