Use freshly brewed hot espresso to fully dissolve the brown sugar and create froth. Shake vigorously to aerate the espresso and chill it quickly. Large ice cubes melt slower to prevent dilution. Barista-style oat milk froths better and adds creaminess. Optional flavor boosters include cinnamon or vanilla extract. For less sweetness, reduce brown sugar or substitute with maple syrup or sugar alternatives. Can substitute espresso with cold brew concentrate or decaf versions.