Line a 20cm x 30cm baking tray with a sheet of greaseproof paper. Mix together the yoghurt, vanilla bean paste and honey in a small bowl.Thinly slice the bananas into rounds and arrange three quarters of them on the prepared tray in a single layer. Spread the yoghurt evenly over the top. Dollop the peanut butter over the yoghurt and swirl using a table knife. Cut the remaining banana slices into quarters and halves, roughly chop the peanuts and scatter both over the yoghurt. Drizzle over the caramel sauce.Freeze for at least 4 hours, or until firm, then snap the bark into pieces and serve. It will last in the freezer for up to 7 days in a sealed container.