Preheat the oven to 180c /gas Mark 4.
In the large bowl, combine all the dry ingredients.
Add the banana, milk, vanilla, vinegar mixture and the peanut butter. Stir thoroughly until you have a smooth, thick batter. Stir in the flax eggs.
Now add the wet mix to the dry, stir to combine well. Now fold in the choc chips.
Grease a loaf tin with coconut oil then spoon in the batter. Smooth out to the edges.
Bake for approx. 45 minutes, check that it’s cooked by sticking a skewer into the middle to ensure it’s cooked through. If not, pop back in the oven until cooked in the middle.
Let it cool for at least 20 minutes, then turn out.