Combine 1 cup water and 3/4 cup granulated sugar in a pot and bring to a boil, stirring occasionally until the sugar completely dissolves. Remove from heat and immediately add 1 1/2 cups tightly packed fresh mint leaves, stirring gently to submerge them. Cover the pot and let it steep for 1 hour at room temperature—this allows the mint flavor to fully infuse into the syrup. After steeping, strain the syrup through a fine-mesh strainer into a clean jar, pressing gently on the mint to extract all the liquid, then discard the spent mint.

In a large pitcher, gently press the stems removed from 2 bunches of fresh mint with the back of a spoon to release their oils and aroma—this shouldn't be a vigorous muddle, just enough to bruise the leaves slightly. Pour in 32 fl oz of Maker's Mark bourbon and add the cooled mint syrup from Step 1, then stir to combine. I find that letting this mixture sit for 15-20 minutes allows the flavors to meld beautifully before serving, but it's ready to use immediately if needed.

Place crushed ice into each serving glass, filling it generously—the ice will help chill the cocktail quickly and keep it cold throughout drinking. If you don't have pre-crushed ice, wrap a handful of ice cubes in a clean kitchen towel and strike with a mallet several times to break into smaller pieces.

Pour 3 ounces of the bourbon-mint mixture from Step 2 over the crushed ice in each glass, then top with 4-5 ounces of San Pellegrino sparkling water (the exact amount depends on your glass size and preference for strength). I like to add a dash of Angostura bitters to each drink right before serving—it adds subtle complexity and a beautiful visual touch. Stir gently to combine, then garnish with a sprig of fresh mint and a light dusting of powdered sugar for an elegant presentation.