01 -
Slice the peeled bananas into a medium bowl and roughly mash them with a fork. Drizzle with lemon juice and set aside.
02 -
In a medium-large skillet over medium-high heat, add water and both sugars. Whisk continuously until sugars dissolve completely and the mixture reaches a low boil.
03 -
Stir in the mashed bananas, vanilla extract, cinnamon, and rum. Mix until fully incorporated.
04 -
Lower the heat to maintain a gentle simmer. Cook, stirring occasionally and further mashing the bananas, for about 30 minutes until the mixture thickens and coats the back of a spoon.
05 -
Transfer the thickened jam into glass mason jars. Cool completely before refrigerating; the mixture will continue to thicken as it chills.