Combine all ingredients with ice in a cocktail shaker. Shake vigorously and strain into a coupe glass. Technically, no garnish is necessary, but everything looks better with a lemon twist, right?
*If you can’t find true crème de violette in your area you can substitute it with Crème Yvette, which also contains violets along with other berries. Crème Yvette is more similar to Chambord in color, and thus the cocktail will not retain the same bluish purple color as with crème de violette.