Gently cook the ground nuts in a large frying pan with the sugar and breadcrumbs, stirring constantly until golden. Remove from the heat and leave to cool.
Put the peaches in a food processor or blender and blend with enough of the peach juice to make a thick, smooth purée.
Fold the blueberries gently into the purée and spoon into 4 glasses or individual serving dishes. Set aside some of the blueberries to decorate.
Whip the cream with the vanilla seeds and icing sugar until thick but not stiff and spoon evenly over the peach purée. When the crunchy topping is cool, sprinkle it over the blueberry mixture, top with the remaining blueberries and serve.