Instructions

1. Heat the oven to 180°C. Line a small (22x22cm) baking tin.
2. Mash the bananas with a fork or blend them in a blender.
3. Add the oats, grated apple, oil and spices. Mix well. Add more oats if needed. You should have a thick batter, but not a dough. Stir in the chestnuts. Let it rest until the oven warms up.
4. Transfer the mixture to the tin, spreading it out evenly, then bake for 25 minutes.
5. Leave it to cool in the tin for 10 minutes, then transfer it to a wire rack and let it cool completely.
6. Cut it into bars or squares.
7. Store the slices in a cake tin.