In a medium saucepan over medium heat, combine sugar and water. Stir until sugar has dissolved. Do not let boil.
Remove from heat and add the cinnamon sticks. Let rest for 15 minutes, stirring occasionally. Leave in longer for a stronger flavor.
Store in a mason jar for up to one month. Leave the cinnamon sticks in the jar for a stronger flavor, or discard them.
Notes
Sugar swap: I use half brown sugar and half granulated sugar, but you can all of either type if you prefer. Ground cinnamon variation: Feel free to make this syrup with ground cinnamon. Sprinkle in 1 tablespoon of ground cinnamon. Stir well. Let it infuse just the way the recipe calls for. Then strain through a fine mesh strainer or coffee filter. (If you skip straining, it may be gritty and grainy, but it will still taste great!)