Preheat the oven to 350°F (180°F) fan. Grease a small loaf pan with coconut oil and line it with parchment paper.
Add the bananas, sugar, coconut oil (no need to melt it if solid), plant-based milk, apple cider vinegar, and vanilla extract to a blender or food processor and blend until smooth. You can also add it to a mixing bowl and blend it with a stick blender or mash it with a fork (in that case we recommend melting the coconut oil and letting it cool down before adding it to the other ingredients).
If using gluten-free oats, whole almonds and whole flaxseeds, grind them in a high-speed blender or food processor. Add the oat flour, almond flour, flaxseed meal, baking powder, baking soda and salt to a separate bowl and mix until well combined (see post above for step-by-step pictures).
Gradually add the dry ingredients to the wet and stir until combined. Fold in the chocolate chips.
Pour the banana bread batter into the greased loaf pan. Top with some extra chocolate chips.
Bake for 45 minutes. Insert a knife into the banana bread to check if it's done. If it comes out clean (it can be covered with chocolate but not with cake batter), take it out of the oven and allow it to cool. Let cool down completely before slicing as the texture will improve while cooling.