Make the peaches: Place the water, sugar, and vanilla bean in a medium saucepan. Stir over medium heat until the sugar has dissolved. Once the sugar has dissolved, remove the vanilla bean and scrape the inside of the bean into the liquid. Add as many peaches to the pan as it will hold without piling or crowding, and poach over a low simmer for about 8 minutes or until the fruit is soft. Remove the peaches and finish poaching the remainder of the fruits. When done, place the peaches in a glass baking dish, cut side down. Pour the vanilla syrup over the peaches, and refrigerate until chilled, for up to 8 hours.
For the yogurt: Place the water and sugar in a small saucepan, stir and simmer until sugar is dissolved. Add the mint leaves and simmer for 2 minutes, remove from heat, cover and let stand for 5 minutes. Strain and chill the syrup.
In a bowl, whip the syrup and cream with a hand-held mixer until stiff. In another bowl, whip the yogurt until smooth and fold it into the cream mixture.
To serve the peaches: Place 2 peach halves in a shallow bowl, and dollop with some of the minted yogurt cream. Garnish with fresh mint sprigs and raspberries.
Recipe adapted from Donna Hay, Flavours, Whitecap Ltd, 1999