Brew your espresso. Pull 2 shots (about 2 ounces total). If using strong coffee, make it as concentrated as possible. Let it sit for 30 to 45 seconds so it’s hot but not scalding.
Prep your shaker. Add 1 heaping cup of ice to a cocktail shaker or a mason jar with a tight lid.
Pour in the brown sugar syrup, vanilla (if using), and a tiny pinch of salt.
Add the espresso. Pour the hot espresso directly over the ice and syrup. This melts just enough ice to balance the flavors.
Shake hard for 15 to 20 seconds. You want vigorous shaking to aerate the espresso and build that fine, silky foam. The shaker should feel frosty.
Strain into a glass with fresh ice. Using fresh ice helps preserve the foam and keeps the drink crisp.
If you like little ice shards, skip straining.
Top with milk. Pour 2 to 4 ounces of cold milk or non-dairy milk over the shaken espresso. Stir gently to keep the foam intact.
Finish with a pinch of cinnamon. Optional, but it complements brown sugar and espresso beautifully.
Taste and adjust. Add a splash more syrup if you want sweeter, or extra milk to soften the intensity.