In a cocktail shaker, muddle lime zest and mint leaves until very fragrant, about 15 times. Add rum, lime juice, and Mint Simple Syrup. Add ice. Stir vigorously until well combined and drink is cold, about 30 seconds. Strain into Collins glass over ice.
Add club soda, and gently stir to combine. Garnish with mint and lime slice, if desired.
Mint Simple Syrup
In a small saucepan, bring mint, sugar, and 1 cup water to a boil over medium-high heat. Remove from heat, and let stand for 20 minutes. Strain through a fine-mesh sieve, and refrigerate for up to 1 month.
Recipe by Louisiana Cookin' at https://louisianacookin.com/mojito/