Whisk together the condensed milk, whipping cream, rum, banana extract, and cinnamon in a large measuring cup. Refrigerate until cold.
Turn your ice cream machine on and pour in the cold cream mixture. Churn until the mixture looks slushy like soft serve, about 12 to 15 minutes.
Transfer the ice cream to another container and put plastic wrap on top of the ice cream. Cover the container tightly with a lid. Freeze for several hours until firm enough to scoop.
Serve over sliced bananas with a drizzle of warm Rum Sauce, and whipped cream.
Melt butter in saucepan. Stir in sugar and stir until it dissolves. Whisk in whipping cream, corn syrup, rum, and cinnamon. Simmer for a few minutes so the flavors can marry. Remove from heat and cool slightly before serving.