Preheat the oven to 160°C fan. Combine all the ingredients in a big bowl, adding the wet ingredients first and then sifting in the dry ingredients.
Grease a tin, with a little oil, or coconut oil. Fill with the mix and top with the bananas sliced in half, push them a little into the mix. Bake for 50 mins, or until cooked through (you can test with a skewer). Remove from the oven and transfer to a wire rack.
Remove from the oven and transfer to a wire rack. Serve slightly warm from the oven.