Fill a cocktail shaker with ice. Pour in all of the ingredients except for the grenadine. Shake vigorously and strain into a glass well stocked with ice (a rocks glass works well). Drop the grenadine over the ice cubes and serve immediately.
Notes
Use a syrupy grenadine to ensure a good “spill” onto the ice, noting that it’s important to have enough ice in the glass for the grenadine to make the fun effect.Get creative I sing the grenadine for different dramatic effect, for example, tilting the glass slightly to drip the grenadine down the inside of the glass will create an effect that pools at the bottom of the glass.This effect will work in any blue colored cocktail, so feel free to substitute these ingredients with your favorite blue drink!