1 fluid ounce sparkling water, or to taste
1 teaspoon clear mint syrup
1 teaspoon white sugar
1 fluid ounce brewed espresso
1 tablespoon whole milk, or as needed
2 leaves fresh mint, or to taste
Mix sparkling water and mint syrup together in a tall glass. Add 2 ice cubes and sugar; stir well. Add more ice to the glass.
Gently spoon espresso into the glass; add milk. Garnish glass with mint.