1 ounce gin
1/2 ounce freshly squeezed lemon juice
1/2 ounce simple syrup
3 ounces Champagne lemon twist, for serving
Place gin, lemon juice, and simple syrup in a cocktail shaker filled with ice. Cover and shake until well chilled.
Strain into a coupe glass or flute and top with Champagne.
Garnish with lemon twist.