Stir together water, mashed banana, brown sugar, white sugar, maple syrup, cinnamon sticks, nutmeg, and salt in a medium saucepan and heat to a simmer.
Once simmering, allow to simmer for 5 minutes, stirring occasionally.
Remove from heat and allow to cool for 15 minutes at room temperature.
After cooling time, strain the solids from the syrup, reserving the syrup and discarding the solids.
Stir in the vanilla extract and transfer to a syrup bottle or mason jar. Store in the fridge for up to 2 weeks!