Maz I do not think there is a difference.:) Sorry for the wrong information. I am just starting to learn about chocolate and there is a lot of different information on it out there. Check out a post I made with more info about cacao. http://www.thecandidadiet.com/forum/yaf_postst2973_Almond-Carob-Coconut-Balls-Stage-23.aspx
It believe it is the same thing. Just different words. Here is a website: http://www.allchocolate.com/understanding/cacao-vs-cocoa/
And another: http://www.ehow.com/about_5398517_cocoa-powder-vs-cacao-powder.html
Some people think “cacao powder is much better for you, the main differences being that ‘cacao powder’ specifically refers to raw, unsweetened powder. ‘Cocoa powder,’ on the other hand, may still have a very small amount of cocoa butter present to enhance the flavor subtly.”
So I guess I would use Cacao powder because of this, but I am sure it does not matter much.
Though after researching cocoa and cacao there is no caffeine in either but rather Theobromine. “It contains a bitter alkaloid named Theobromine that is similar to Caffeine but not quite the same. In general it produces less intense and more beneficial effects…but it can still keep you up! Theobromine is much more gentle on the central nervous system and adrenal systems than caffeine but is more stimulating to the heart. “
There is much debate on Theobromine. You might want to check out the other links under the first post I gave.