Place the sugar and water at the bottom of a julep cup or tall glass and stir until sugar is dissolved (or speed the process by using simple syrup). Add the mint leaves and gently bruise with a wooden muddler or a wooden spoon. Take care not to overwork the mint, but swab the sides of the glass with the mints aromatic oils. Half-fill the glass with crushed ice and add the bourbon, stirring to combine. Fill the glass with crushed ice and stir until the outside of the glass frosts. Add more crushed ice if needed to fill, and generously adorn the drink with sprigs of fresh mint. Serve with a short straw, and enjoy immediately!