Stir the water, lemon zest, lime zest, orange zest, cinnamon sticks, dried orange peel, whole coriander seed, nutmeg, and green bean coffee powder (if using) in a large saucepan over medium heat.
Stir in the sugar and bring to a boil.
Continue stirring until the sugar dissolves. (The green bean powder will not dissolve completely)
Boil for one additional minute, then remove from the heat.
Add the lemon juice, lime juice, orange juice, browning sauce, and pure vanilla extract to the saucepan mixture.
Let mixture cool, then use a fine mesh strainer and strain syrup into a mason jar or other sealable bottle for storage.
To make one cola drink: Combine 1/2 cup of the cola syrup with 1 1/2 to 2 cups of seltzer water (pour slow as the mix will fizz, just as regular soda).
Add ice, if desired, and serve.