Preheat oven to 350 degrees, and grease loaf tin with coconut oil. Prepare flax eggs and leave to sit for 5 minutes.
In a medium bowl, mash bananas until smooth. In a separate bowl, combine spelt flour and baking soda.
Add coconut sugar, melted & cooled coconut oil, and vanilla extract to mashed bananas. Finally, add flax eggs to this wet mixture once they have thickened up (should take around 5 minutes).
Add flour mixture to wet ingredients and mix until thoroughly combined. Chop bar of chocolate, and fold chunks into batter (or alternatively use chocolate chips).
Transfer to prepared loaf tin or mini loaf tins. Add more chocolate chips to the top of the loaf/loaves. Bake for 30 minutes on 350 degrees or until knife/toothpick in center comes out clean!