Crush the bran flakes and mash the bananas. (I put the cereal in a food grade plastic bag and used a rolling pin to crush the cereal)
In a medium size, bowl mix together the bananas, egg, milk, oil, and cereal. Set aside and let rest for about 5 minutes.
In a large bowl whisk together all the dry ingredients. Add the banana mixture to the dry ingredients and stir until just moistened.
Spoon the batter into 12 prepared muffin cups and bake for 20 – 25 minutes, or until a toothpick inserted comes out clean. Remove to a wire rack to cool.