Heat oven to 400 F.

Leaving the skin on the bananas, slit the bananas along the top almost all the way to the ends so they still stay intact.

Place on a cookie sheet and bake for 15 minutes or until the insides of the bananas are soft and starting to bubble.

In a medium-sized mixing bowl, beat butter, brown sugar, and salt until smooth.

Mix in the eggs and egg yolks one at a time until just combined.

Mix in the roasted banana a little bit at a time. The mixture may separate a little at this point and that is fine.

Transfer the mixture to a small pot on medium-low heat. Stir regularly until the mixture reaches 175 F on a candy thermometer, about 20 minutes. It should be bubbling periodically, but not at a fast-paced boil.

Remove from the heat and transfer to a blender.

Add rum and cinnamon and blend until smooth. Press plastic wrap directly onto the surface of the curd and poke a few holes in it to let the steam release. Refrigerate until ready to use.