"This pina colada is like a dream in a glass-it is 25% dessert, 75% tropical vacation, and 100% adult beverage. You can hear the Pacific from Omaha if you have one of these in your hand. Enjoy! You can substitute coconut-flavored pancake syrup for the cream of coconut."
Pour the light rum, amber rum, pineapple juice, sweet and sour mix, cream of coconut, and half-and-half cream into the pitcher of a blender with ice; blend until the cocktail has a slushy texture. Pour the slushy mixture into a glass.
Slowly and gently drizzle the dark rum over the drink so it just floats on top; serve.