Muddle the Strawberries and Mint: In a cocktail shaker or a sturdy glass, muddle the sliced strawberries and mint leaves together until they release their juices and aromas.
Add the Rum, Lime Juice, and Simple Syrup: Pour in the white rum, freshly squeezed lime juice, and simple syrup (adjust the sweetness to your preference).
Shake or Stir: Fill the shaker or glass with ice cubes, then shake vigorously or stir until well combined and chilled.
Strain into a Glass: Strain the mixture into a highball glass filled with ice cubes, using a fine mesh strainer if necessary to remove any pulp or seeds.
Top with Club Soda: Top the cocktail with club soda or sparkling water, leaving some room at the top of the glass.
Garnish and Serve: Garnish the cocktail with a fresh strawberry and a sprig of mint for an extra touch of freshness and aroma. Optionally, you can also add a lime wedge for an additional pop of color and flavor.