The one I made came out just right, it wasn't too bitter or too sweet... just right! Thank you for sharing.
I followed Missy Wombat's suggestion and used 1 tblsp off cocoa only and dissolved the cocoa in a tiny amount of hot water. When i 1st blended it up I didnt realy like the taste of raw cocoa I added some vanilla essence and serving it with ice cubes made a big diffrence.
Two tablespoons of cocoa was a little much in my book and didn't add anything to the drink. One tablespoon would have the same effect. Using a touch of hot water to dissolve the cocoa first would also help.