This addition immediately brightens the drink. The orange liqueur provides a fresh burst of citrus tartness and sweetness, while the soda water gives the drink a crisp zing.
To make it, mix two ounces of whiskey, ¾ ounces of fresh lemon juice, ½ ounce of orange liqueur, and ¼ ounce of simple syrup. Top it with club soda and an orange peel garnish.
Once you've got all of these elements together, add the whiskey, lemon juice, liqueur, and simple syrup to a cocktail shaker with ice. Shake it up and then strain the drink.