1½ tablespoons dark rum, OR 1½ teaspoons rum extract
Instructions
In a heavy saucepan over medium heat, combine the cream and half and half heating until just simmering, stirring frequently. Turn the heat down to low.
Whisk together the egg yolks, sugar, and salt in a large bowl until thoroughly combined.
Slowly and carefully pour about ½ cup of the cream mixture into the egg yolk mixture with one hand, while whisking constantly with the other. Pour the egg mixture back into the saucepan with the remaining hot cream, and whisk constantly over medium-low heat until the mixture thickens and will coat the back of a spoon, 5 to 8 minutes. Do not let mixture boil.
Pour the custard base into a bowl and allow to cool while you prepare the bananas.
In a large skillet, over medium-high heat, melt the butter. Add the brown sugar and whisk together until the sugar as dissolved into the butter.
Add the bananas, stirring to coat them in the butter/sugar mixture. Reduce heat to medium and cook for about 5 minutes, until bananas are tender. Add the rum and cinnamon and stir well, simmering for an additional 2 minutes.
Add half of the banana mixture to the custard base, using an immersion blender right in the bowl to pureé until smooth. (You can also carefully pour the custard and bananas into a regular blender and pureé that way.)
Cover the custard mixture and chill in the fridge for 6-8 hours or overnight.
Use a wooden spoon to slightly break the remaining banana pieces up, and store them in the fridge until after you churn your ice cream.
When the custard is chilled- churn it according to your ice cream maker's instructions and layer it with the remaining banana mixture in your container. Freeze for a few hours to firm it up.