In a small microwave safe bowl add butter. Melt in the microwave until hot, not just melted.
Add the brown sugar, cinnamon, rum and vanilla. Mix well.
Peel the bananas. Cut them in half in the center, then length wise so they are quartered.
Add the bananas to the slow cooker, cut side up. Drizzle over the sauce trying to coat the bananas well. If there are some dry spots on the bananas, spoon over the sauce or flip the banana so they are coated.
Place the lid on the slow cooker. Cook on HIGH for 45 minutes to an hour. Turn off the slow cooker after cooking time up , not a great recipe to keep on warm, they will turn to mush. But will keep at a perfect temperature just sitting in the slow cooker off for about 30 minutes.
Serve with 3-4 banana pieces and top with ice cream. Drizzle over the sauce from the slow cooker.
Notes
To make alcohol free: instead of adding a light or dark rum, you can add a rum extract instead. Another option is to substitute the rum using heavy cream.
Serve promptly, and turn off the slow cooker when ready to serve. For the bananas will continue to cook and turn mushy.
The bananas can be cut into slices (rounds) instead of long pieces if desired.
Nutritional values do not include ice cream.
You can easily double this recipe to feed more people! The cooking time will only need to increase about 20 minutes.