Step 1
In a small saucepan, bring brown sugar, water, and cinnamon stick to a boil. Stir constantly until sugar dissolves. Reduce heat and simmer for 6 to 8 minutes. Remove from heat and allow to cool.
Step 2
Fill a tall glass with ice. Pour in brown sugar syrup and freshly brewed espresso and stir. Pour oatmilk into the glass. Sprinkle with a dash of ground cinnamon as garnish.
Brown sugar syrup can be stored in the refrigerator up to 10 days. Freshly brewed espresso can be substituted for cold brew coffee concentrate.