1/2 oz of Gin
1/2 oz of Vodka
1/2 oz of creme de cacao (or chocolate liqueur)
1/4 oz of grenadine syrup
1/2 oz of blue curacao liqueur
1/2 oz of Midori melon liqueur (or watermelon liqueur)
4 oz of half-and-half (or cream)
Blend all the ingredients apart from the Grenadine. Pour that on top of the drink when its in the glass.