Combine the sugar and cinnamon until thoroughly combined.
Place in an airtight container for storage.
Notes
Scale the recipe as needed, keeping the ratio of sugar to cinnamon at 4:1 by volume.
*You can instead use a coarse sugar, superfine sugar, brown sugar, or confectioners' sugar, depending on how you will use it. See my notes above the recipe for more info.
**For a a weaker or stronger cinnamon sugar, use a bit less or a little more cinnamon.