Preheat oven to 180 degrees Celsius. Line a baking tin with baking paper.
In a medium sized mixing bowl add mashed bananas, linseed meal, water, olive oil and milk. Whisk to combine.
Add buckwheat flour, tapioca, coconut sugar, baking powder and cacao powder to a large mixing bowl. Whisk to combine.
Pour the banana mixture into the flour mixture and stir until just combined. Pour into loaf tin and bake for 50 minutes at 180 degrees Celsius. The loaf is baked once a skewer comes out clean when inserted into the centre of the loaf.
Once banana bread is baked, remove from oven and allow to cool in the tin for about 10 minutes before transferring to a cooling rack.
Nutrition facts are an estimate only. Store loaf on counter top for 2-3 days or in fridge for 3-4 days. Alternatively, slice the loaf and freeze in portions.