1. The night before, put the oats, peanut and raisin mix and most of the frozen fruit (keeping 2 handfuls to defrost in a small bowl) in a lidded container or large bowl.
2. Coarsely grate in the apples, discarding the cores and stalks. Pour over the milk, mix well, then cover and leave in the fridge overnight.
3. In the morning, loosen the peanut butter with a splash of boiling water, then stir in the honey and yogurt. Transfer the oats to bowls or portable containers. Drizzle with the peanut butter mix and top with the reserved fruit.