This delicious tweak on a classic is from Hip Sips by Lucy Brennan (Chronicle Books, Spring 2007) and was featured as a Cocktail of the Month.

Ingredients

　　2 ounces light rum

　　2 ounces gold rum

　　1/2 ounce fresh lemon juice

　　1/2 ounce fresh lime juice

　　2 ounces simple syrup

　　1/4 medium-ripe avocado, peeled and pitted

　　1/2 ounce half-and-half

　　1 1/2 cups ice

　　Combine ingredients in blender and blend on high until just smooth, about 20 seconds. Divide mixture between two cocktail glasses and serve.