In a large mixing bowl combine the chopped strawberries, sugar, lemon juice, and vanilla. Cover with plastic wrap and refrigerate for at least 4 hours or even better, overnight.
To serve, add a heaping spoonful of the strawberries and syrup to a glass. Add a few torn basil leaves and muddle to combine. Add ice, and a shot of gin or vodka, as desired. Top with 8 oz of sparkling water and garnish with fresh strawberries. Stir and enjoy!