Preheat the oven or air fryer to 180°C. Line a small loaf tin with baking parchment or prepare two small silicone loaf moulds that fit your air fryer.
Mash the bananas together with half of the chopped peach until mostly smooth.
Add the egg, ground ginger and poppy seeds, then mix well.
Stir in the wholemeal flour and rolled oats until combined. If the batter seems too thick, add a splash of milk or plant-based milk.
Gently fold in the remaining peach pieces.
Spoon the mixture into the prepared tin or moulds and level the surface.
Bake in the oven for about 40 minutes, or until the cake is lightly golden and a skewer inserted into the centre comes out clean.
Alternatively, bake in the air fryer for about 25 minutes, checking that the centre is cooked before removing.
Leave the cake to cool in the tin for 10 minutes before transferring it to a wire rack to cool completely.
Slice and serve.