Heat oven to 180°C (350°F) and fold a 20 cm (7.9 inches) loaf pan with parchment paper or grease with oil.
In a large bowl, mash three ripe bananas with a fork until completely smooth. Stir the eggs, the nut butter and the oil into the banana mixture.
Add in the coconut sugar, the vanilla extract, the cinnamon and the salt. Stir the wet mixture with a whisk or fork for around two minutes, or until all is well combined.
Sift in the oat flour and the baking powder. Give it a good stir until all is well combined.
Pour the batter into your prepared loaf pan and bake in hot oven for 30 to 40 minutes. Or until a toothpick inserted into the center of your oatmeal banana bread comes out clean.
Remove from the oven and let cool in the loaf pan for about 15 minutes. Be sure to let it cool completely before slicing and serving.