In a saucepan over medium heat, cook banana slices with ¼ cup water and ¼ cup sugar until browned, about 10 minutes. Stir in a pinch of cinnamon.
Reduce heat to low. Stir in ¾ cup sugar and ¾ cup water until sugar has dissolved.
Remove from heat. Strain through a fine-mesh strainer and discard the solids. Let cool completely.
Banana Old-Fashioned
In a mixing glass filled with ice, combine aged rum and banana syrup.
Use a bar spoon to gently stir the mixture until chilled.
Strain into a rocks glass with a large ice cube or sphere.
Top with a few dashes of cinnamon bitters and garnish with a brûléed banana slice.
Notes
To make caramelized banana garnishes for your cocktails, place a banana slice on a heat-proof surface. Sprinkle a pinch of granulated sugar over a banana slice and brûlée with a kitchen torch.For a non-alcoholic version, use a zero-proof spirit in place of the rum and non-alcoholic bitters.