1.In a medium skillet over medium low heat, melt the butter. Once the butter is melted, add the brown sugar, molasses, and rum. Mix well to dissolve in the butter. Add the mashed and sliced bananas. Stir well until the bananas start to look glossy and softened. Remove the banana mixture from the heat and allow it to cool for 10 minutes.
2.Preheat oven to 350 degrees. Spray a 12 count muffin pan with non-stick spray. In a small bowl, combine flour, baking powder, cinnamon, and salt. Whisk together and set aside.
3.In a large mixing bowl, add the egg, egg white and vanilla extract. Whisk well until thoroughly combined. Once the banana mixture is cooled, add it into the egg and vanilla mixture. Stir well to combine.
4.Carefully fold in the dry ingredients and divide batter into muffin pan. Bake for 25 minutes.