1. Preheat the oven to 180°C (350°F) fan-forced. Line a 23x12cm loaf tin* with baking parchment and grease lightly. Set aside.

2. For the batter, add both flours, xylitol (or sugar), baking powder, baking soda, cinnamon, cardamom, rolled oats, chopped walnuts, and chia seeds to a large bowl and mix to combine. In a second bowl mix eggs, buttermilk, rapeseed oil, mashed bananas, and grated zucchini until well combined. Add the wet ingredients to the bowl with the dry ingredients and mix (with a rubber spatula) until just combined. Transfer the batter to the prepared loaf tin.

3. For the topping, peel the mini bananas, half them lengthwise and place them on the batter. Mix the rolled oats, chia seeds, brown sugar, cinnamon, and cardamom and sprinkle over the dough and mini bananas. Bake the banana bread for about 55-65 minutes, or until a wooden skewer inserted into the center of the banana bread comes out clean. If the banana bread gets a little dark, simply cover it with some baking parchment or aluminum foil and continue baking. Take finished banana bread out of the oven and let it cool down inside the baking tin for some time, then remove and let cool down completely on a wire rack.