Chill a coupe or rocks glass by filling it with ice or placing it in the freezer. In a cocktail shaker add 2 oz Ketel One Vodka, 0.75 oz fresh lemon juice, 1 oz fresh grapefruit juice, 0.5 oz simple syrup, 0.25 oz orange liqueur, and 1 dash Angostura bitters. Fill the shaker with ice (about 3/4 full).

Shake and strain

Secure the shaker lid and shake vigorously for 12–15 seconds until the shaker is very cold and well-aerated. Discard ice from the chilled glass. Double-strain the cocktail into the chilled coupe or a rocks glass filled with fresh ice, using a Hawthorne strainer and a fine mesh strainer to remove small ice shards and pulp.

Optional top and finish

If desired, gently top the drink with 1 oz club soda for a lighter mouthfeel. Give the glass a gentle stir (1–2 rotations) to integrate the soda without losing effervescence.

Garnish

Express oils from a grapefruit twist over the surface of the cocktail by holding the peel over the glass and giving it a quick twist, then rub the peel on the rim and drop it into the drink as a garnish. Alternatively, float a thin grapefruit wheel on top. Optionally add a lemon peel for additional aromatic lift.