In a blender or bowl, combine bananas, maple syrup, cinnamon, salt, and water
Blend or stir until smooth
Pour into a saucepan and simmer over medium heat for 5–7 minutes
Stir occasionally until it thickens slightly and smells caramelized
Remove from heat and stir in vanilla extract or paste. Mix until fully combined
Strain the syrup through a fine mesh sieve to remove solids. Discard pulp and keep the smooth syrup
Let the syrup cool completely
Transfer to a clean, airtight jar and store in the fridge for up to 3–4 weeks