What blessing is said before chocolate? And after?

Chocolate is made from cocoa beans that undergo significant processing, and since it no longer resembles its original plant form, it receives 'Shehakol.' The after-blessing is 'Borei Nefashot.' A general principle: when a food is so processed that it no longer resembles its natural source, the blessing typically reverts to Shehakol rather than the blessing for the original ingredient.