In a small saucepan, combine the mashed banana, maple syrup, water, cinnamon, and salt.
Bring to a gentle simmer over medium heat, stirring occasionally, for about 5–7 minutes until thickened slightly.
Remove from heat and stir in vanilla.
Let cool slightly, then strain through a fine mesh sieve or cheesecloth for a smooth syrup.
Store in the fridge for up to 5 days.
