Mash the two overly ripe bananas thoroughly with a fork until mostly smooth. Add the mashed bananas, brown sugar, white sugar, maple syrup, ground cinnamon, pinch of salt, and water to a medium saucepan set over medium heat.

Stir everything together, bring the mixture to a gentle boil, then reduce the heat and let it simmer for 15 minutes until thickened and fragrant.

Remove the saucepan from the heat and pour the mixture through a fine-mesh strainer into a clean bowl or jar, pressing lightly on the solids to extract all the syrup. Stir the vanilla bean paste into the warm strained syrup until fully combined, then let it cool completely to room temperature.

To assemble the latte, pour two tablespoons of the cooled banana bread syrup into the bottom of a tall serving glass. Fill the glass generously with fresh ice cubes. Pour in your milk of choice, leaving a little room at the top, and pour one to two freshly brewed shots of espresso over the milk. Stir well to combine the sweet banana syrup with the espresso and milk, and serve immediately.