Peel and mash bananas in a medium bowl, leaving some chunks for texture.

In a saucepan, combine bananas, brown sugar, lemon juice, vanilla, cinnamon, and salt.

Cook over medium heat until mixture bubbles gently, then reduce to low and simmer 25–30 minutes.

Stir in dark rum and cook an additional 5 minutes.

Test consistency on a chilled plate; simmer longer if needed.

Cool slightly and transfer to sterilized jars. Store in the refrigerator up to 2 weeks.