Preheat oven to 350F (175C)
In a large mixing bowl, mash bananas into a paste that does not have any chunks. Add the melted butter and stir.
Mix in the baking soda, salt, sugar, beaten egg, vanilla extract, nuts, and diced jackfruit,. When this is mixed well, add the flour and mix again until uniform throughout.
Transfer the mixture to an oiled baking tin. I recommend a metal loaf tin.
Bake at 350F for 50 minutes to 1 hour. If you choose to bake your mixture in smaller forms, you can reduce the baking time.
When baking is finished, remove from the oven and let cool for a few minutes before slicing and serving. Banana jackfruit bread is best served warm!