In a medium saucepan, combine the water, mashed bananas, brown sugar, sugar, maple syrup, cinnamon sticks, nutmeg, salt, and ground ginger. Bring the mixture to a gentle simmer over medium heat, stirring occasionally to dissolve the sugars completely. Once simmering, maintain a gentle simmer for 5 minutes—this allows the spices to infuse their flavors into the liquid while the banana breaks down further. I always use Nielsen-Massey vanilla extract, and I add it at the end rather than now because heat can diminish its delicate aroma.

Remove the pan from heat and let the syrup cool for about 15 minutes at room temperature. This cooling period allows the flavors to fully develop and makes straining easier. Pour the mixture through a fine-mesh strainer set over a bowl or measuring cup, pressing gently on the banana solids with the back of a spoon to extract as much flavorful liquid as possible, then discard the solids and cinnamon sticks. I like to let the strainer sit for a minute or two to capture every last drop of syrup—it's too delicious to waste!

Stir the vanilla extract into the strained syrup until fully combined. Transfer the finished syrup to a clean bottle or container and let it cool completely before sealing. The syrup will continue to thicken slightly as it cools, reaching a perfect pourable consistency.