In a small skillet, melt the butter over medium heat.
Add the brown sugar and cinnamon, stirring until the mixture is bubbly and well combined.
Slice the banana in half lengthwise and place it cut-side down in the skillet.
Cook for about 2 minutes until the banana is slightly caramelized.
Carefully flip the banana and cook for another minute.
Add the vanilla extract and rum, if using, and let it cook for an additional minute, allowing the alcohol to cook off.
Remove the skillet from heat and place the banana on a plate.
Pour the sauce over the banana and serve immediately with a scoop of vanilla ice cream on the side.