In a cocktail shaker, combine gin, freshly squeezed lemon juice, and simple syrup. Fill the shaker with ice cubes and shake vigorously for 10-15 seconds to chill the ingredients. Strain the mixture into a chilled champagne flute or coupe glass. Top it off with chilled sparkling wine, filling the glass almost to the rim. Give it a gentle stir to combine the ingredients.

Garnish with a twist of lemon peel, adding a touch of aroma to the cocktail. Serve immediately.