Heat a large skillet over medium-high heat.
Add butter and when it begins to foam, add bananas and sugar.
Sauté and let bananas caramelize.
When they are golden and while the pan is hot ignite them.
Tilt the pan away from you, pour in rum and hold a match over the simmering mixture. Be careful!
When the alcohol has burned off, the flame will die down.
Serve over vanilla ice cream.