Chill a cocktail glass with ice water and set aside.
Combine gin, cognac, crème de cassis, and fresh lemon juice in a cocktail shaker.
Fill the shaker with ice and shake vigorously for 12–15 seconds until well chilled.
Discard the ice water from the chilled glass.
Double-strain into the chilled cocktail glass.
Serve immediately, ungarnished.
The balance between gin and cognac is the soul of this drink - use a London dry gin for clean botanical structure and a VS or VSOP cognac for stone-fruit warmth without overpowering oak. A light hand with the cassis keeps it sophisticated rather than sweet.
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