Using lemon slice, moisten the rim of a chilled cocktail glass; set lemon aside. Sprinkle sugar on a plate; hold glass upside down and dip rim into sugar. Discard remaining sugar on plate. Fill a shaker three-fourths full with ice. Add vodka, limoncello and lemon juice; cover and shake until condensation forms on outside of shaker, 10-15 seconds. Strain into prepared glass. Garnish with lemon slice.
Test Kitchen Tips
Go for freshly squeezed lemon juice when preparing this summery sipper. Bottled lemon juice, which is from concentrate, won’t provide the same bright, fresh flavor. Buy fresh lemons to get the job done.