1. Prepare the Rambutan - Peel the rambutan fruit and remove the seed from the center. Set the flesh aside. - Rambutan can be messy to handle, so it's best to wear gloves or use a paper towel to grip the fruit. If rambutan is not available, lychees or other tropical fruits can be used instead.

2. Muddle the Mint and Lime - In a cocktail shaker or mason jar, muddle the mint leaves and lime juice until the leaves release their aroma and oils. - Muddling is the process of gently crushing the mint leaves with a muddler or the back of a spoon. Be careful not to over-muddle, as this will make the drink bitter.

3. Add Rambutan, Rum, and Simple Syrup - Add the rambutan flesh, white rum, and simple syrup to the shaker and fill it halfway with ice. Shake vigorously for 10-15 seconds to chill and mix the ingredients. - To make simple syrup, heat equal parts sugar and water in a saucepan until the sugar dissolves. Let it cool before using. White rum can be substituted with other types of liquor, but it's important to use a clear liquor for the color contrast with the rambutan.

4. Strain and Serve - Strain the cocktail into a glass filled with ice and top it with club soda. Garnish with a slice of lime and more mint leaves, if desired. - To strain the cocktail, position a strainer over the shaker or use a shaker with a built-in strainer. Club soda can be substituted with tonic water or sparkling wine for a different flavor profile.