Warm the apple juice in a small saucepan with the split vanilla pod and agave nectar or sugar over a medium-low heat. Simmer gently for 4–5 minutes, then leave to cool completely. Remove the vanilla pod and scrape the seeds into the light syrup.
Combine the fruits in a large bowl and drizzle over the vanilla-spiced syrup. Stir gently to coat and spoon into serving bowls. Sprinkle with mint leaves and serve.