In a cocktail shaker combine 4 raspberries and cilantro. To muddle, crush berries and cilantro with the back of a spoon. Add gin, lemon juice, Simple Syrup, and ginger liqueur. Add ice cubes; cover and shake until very cold. Strain liquid into an ice-filled glass. If desired, garnish with additional raspberries.
In a small saucepan combine sugar and water. Bring to boiling over medium heat, stirring until sugar is dissolved. (The syrup is done when it is completely clear and the surface is covered with bubbles.) Remove from heat; cool. Store, covered, in the refrigerator up to 2 weeks.