Brew 3 shots of espresso using your preferred method. See my 5 Ways To Make Espresso At Home blog post for step by step instructions of each espresso making method! To a cocktail shaker cup or mason jar, add the brown sugar syrup, espresso, ground cinnamon and ice.
Add the lid and shake until the entire cup is cold to the touch and the mixture is frothy.
Pour the mixture into a separate cup (if using a cocktail shaker).
Add oat milk over the top, and enjoy!