You will need a blender!
Ingredients:

1 large or 2 medium sized ripe avocados
1 cup low fat 2% milk or 1 cup nonfat plain yogurt
1 tsp. vanilla (optional)
Sugar, to taste (I use 3 or 4 soup spoonfuls of raw or cane sugar)
1 cup crushed ice (optional)
Chocolate syrup (the kind in the squirt bottle works best!)

Preparation:
Cut open and scoop out insides of avocado, scraping off discolored sections, if any.

Put crushed ice in blender.

Add avocado, milk or yogurt, sugar, vanilla (if used) and put the top on the blender.

Blend on a medium speed until smooth. You don’t want chunky for this!
Squirt a little syrup in the bottom of a clear glass, and then dribble a little of the syrup up the sides as you twirl the glass.

Pour in the milk and avocado mixture.