Add mint leaves and lemon wedges to a sturdy rocks glass and muddle gently to release oils and juice.
Pour in bourbon, fresh lemon juice, and simple syrup.
Fill the glass with crushed ice and stir gently to chill and dilute.
Top with more crushed ice if needed and garnish with a mint sprig and lemon wedge. Serve immediately.
Notes
Muddle lightly to avoid bitterness from torn mint. Choose a smooth, not-too-smoky bourbon so the lemon and mint shine. Adjust sweetness with a touch more simple syrup or add extra lemon for brightness.