Grab a tall glass (highball or Collins) and set out your mint leaves, lime wedges, sugar or simple syrup, coconut rum, white rum (if using), coconut milk, club soda, and ice.

Add the fresh mint leaves, lime wedges, and sugar or simple syrup to the bottom of the glass. Using a muddler or the handle of a wooden spoon, gently press and twist to release the mint oils and lime juice without shredding the mint into tiny pieces.

Pour in the coconut rum and, if using, the white rum. Stir gently to help dissolve the sugar and mix the flavors from the muddled mint and lime.

Pour in the unsweetened coconut milk and stir again until the mixture turns a pale, creamy color. If you prefer a richer drink, add a little more coconut milk or use part coconut cream thinned with a splash of water.

Add ice to the glass, filling it nearly to the top so the drink chills quickly and stays cold as you sip.

Top the drink with chilled club soda or sparkling water. Gently stir from the bottom up to combine without losing too much carbonation. Taste and adjust: add more club soda if it’s too strong, or a little more sugar or syrup if you’d like it sweeter.

Garnish with a fresh mint sprig (lightly smack it between your palms to release aroma) and a lime wheel or wedge on the rim. Optionally, sprinkle a pinch of shredded coconut on top. Serve immediately while cold and bubbly.