Place 8–10 fresh mint leaves into a julep cup. Add the raspberry syrup and gently press the mint with a muddler just enough to bruise the leaves and release their oils - do not shred.
Fill the cup halfway with crushed ice. Pour the bourbon over the ice.
Stir gently with a bar spoon to integrate and chill.
Top with additional crushed ice, mounding it above the rim.
Garnish with a fresh mint sprig, tapping it gently against your palm first to express its aroma. Serve immediately with a straw.
Bruising the mint rather than muddling it aggressively is key - over-muddling releases bitter chlorophyll from the stems and dulls the clean herbal note that defines a great julep. Use a fine, powdery crushed ice for the best dilution and the signature frosted exterior on the cup.
My Bar Shelf reads your shelf and shows you every cocktail you can make from what you already own, including Raspberry Julep.