Slice the bananas into rounds and place them in a large mixing bowl.

Add both sugars, the cinnamon stick, and the lime juice, then mix thoroughly to coat the fruit evenly.

Transfer the mixture to a large saucepan and let it rest for 1 hour, or move straight to cooking if you prefer.

Bring to a boil over high heat, then reduce to low and simmer gently.

Keep an eye on the cooking time – it should not exceed 30 minutes.

Test for setting by placing a few drops of jam on a very cold spoon: if it runs, cook a little longer and repeat the test.

Pour the hot jam into sterilized jars immediately.

Seal tightly and turn the jars upside down to create a vacuum seal.

Allow to cool completely, then store in a cool, dry, dark place.

Once opened, refrigerate and consume within 2–3 weeks.