In a large skillet, melt the butter over medium heat. Add the sugar and cinnamon and stir until all the sugar melts.
Add the sliced bananas, cardamom, vanilla, and rum and stir to blend. Cook for 3 or 4 minutes until the bananas are warm. Turn the heat to low and simmer until the sauce is thickened.
Scoop ice cream into individual serving bowls and top with the bananas and sauce. Serve at once.
Traditionally the bananas are sliced in half and then vertically, but you can simply slice them into bite-size rounds.
The dark rum is optional. It will cook down if it is reduced in the banana flambe caramel sauce.
Also, once the rum is hot, you can remove the skillet from the burner and set fire to the rum to remove the alcohol content but leave the flavor.
This banana flambe mixture will keep up to 4 days in the refrigerator.
Flambe safety tips:
The choice to flambe the bananas is totally optional. When you flambe your bananas it further cooks off the dark rum. To flambe, add the rum, then tilt the pan very slightly so the rum in the bananas catches the flame. (You can also use a LONG fireplace match to start the flame.)
NEVER pour the alcohol into the pan from the bottle. This is dangerous. Pour the measured amount of alcohol into a small dish and pour into the pan from that.
Have a fire extinguisher handy on the counter just in case. There is so little alcohol, it burns off very quickly in just 3-4 seconds.
How to ripen bananas:
Place your bananas on a baking sheet and bake at 225º F for 20 minutes.
If you aren't in a hurry, you can put your bananas in a brown paper bag and let them sit on the counter. (Don't forget to close the bag!)
You can grill the bananas. Just slit down the skin and place on a grill. Close the lid and cook at 300º F for 15 minutes.