Combine bourbon, lemon, lemon lime soda reduction and egg white into a shaker tin. Dry shake for about 30 seconds. Add a large fresh basil leaf and ice. Shake vigorously, strain into a coupe glass and garnish with a basil leaf.To make lemon lime soda reduction: Pour a 2 liter of lemon lime soda into a large saucepan. Cook over medium heat for approximately two hours or until it has reduced down to about a quarter of its volume. Let cool before crafting your cocktail.