Add watermelon to cocktail shaker and muddle to form a puree (press down on the melon with the muddler and turn then repeat about 10 times).
Add ice to fill the cocktail shaker about halfway, followed by gin, elderflower liqueur, and lemon juice.
Cover cocktail shaker and shake vigorously until thoroughly mixed and chilled to touch (about eight seconds).
Strain or double strain cocktail into chilled glass. Garnish with fresh or frozen watermelon and enjoy responsibly!
Notes
PreparationTo make it advance, prepare the drink then store in the refrigerator or freezer until you're ready to sip. To serve, shake it up again then add any garnishes.To big batch this drink, muddle four cups of watermelon in a pitcher or carafe then fill halfway with ice. Pour in six ounces gin, three ounces elderflower liqueur, and two ounces lemon juice and stir or shake to combine. Serves four.To make watermelon lemon drop shots, build this cocktail per the recipe card directions then divide the liquid between three shot glasses.Cocktail Tool SubstitutesIf you don't have a muddling tool, you can use the end of a kitchen spoon to crush the watermelon instead.And you can use a shot glass to measure out your liquids, if needed, since it holds the same volume as the larger end of a jigger.