Preheat oven to 356F (180C) and line a baking loaf tin with parchment paper OR grease with butter and coat with some oat flour for a clean release after baking!
Melt the butter (about 20 seconds in the microwave).
Add the ripe bananas, eggs, raisins, and melted butter to a blender and blend until smooth.
In a medium mixing bowl, combine the oat flour, all-purpose flour, baking powder, and cinnamon.
Whisk the dry ingredients until combined.
Pour the blended wet ingredients into the dry ingredients bowl and whisk until combined.
Pour batter into the greased loaf pan and bake for 25-30 minutes until a tooth pick comes out clean and the banana bread is golden on the edges.
Let it cool 5-10 minutes and move to a wire rack.