In a serving glass, stir together limoncello, vodka, lemon juice, bitters, and ice until chilled, about 15 seconds. Add club soda. Garnish with lemon slices, if desired.
Notes
Kitchen Tip: You can make a pitcher of this drink by increasing the recipe proportionately and stirring together limoncello, vodka, lemon juice, bitters, and ice in a pitcher. Add club soda and lemon slices just before serving.
Recipe by Southern Lady Magazine at https://www.southernladymagazine.com/limoncello-spritzer-recipe/