Brazilian Avocado Chocolate Shake

This is the low cal version of the milkshake my Brazilian friend told me about.
Ingredients
1 ripe avocado
2 tablespoons unsweetened drinking chocolate (like Caotina)
1/4 tsp brown sugar
1 tsp vanilla essence
1 cup milk

Method

1. Cut the avocado in two and scoop out the flesh.
2. Add the chocolate and the rest of the ingredients.
3. Blend until uniform - it will have the texture of melted ice-cream.
4. Drink immediately.

Variation
You can even make it with berries and bananas instead of the chocolate powder.