Preheat you oven to 350 degrees and either line a muffin tin with papers or coat it with cooking spray.
Mash your bananas thoroughly and add in the sugar and oil, stirring to combine. Toss in the cinnamon, salt, both flours, baking powder and soda all at once, and mix just enough to moisten all of the dry ingredients, but there’s no need to be too thorough. Finally, add in the pumpkin butter and stir that well, being careful not to over-mix. The resulting batter should be rather thick.
Spoon the batter into your prepared tins, mounding it up generously in the centers. Sprinkle oats and cinnamon on top as desired, and bake for 15 - 25 minutes until golden brown, and a tooth pick inserted into the middle comes out clean. Let cool on a wire rack and enjoy.