First put a banana or 2 in the freezer to get real cold or even frozen!
Then in a blender mix together:
- Banana
 - Peanut Butter
 - Cocoa Powder
 - Sweetener of your choice (only use a tiny bit, the bananas are sweet enough on their own)
 - Ice
 - Milk of your choice (I use soy milk)
 
Pour in to a tall glass, add a straw and enjoy!