Then, after only a few bites, he changed his mind. According to him, it hurt his throat and his ankle.
So we gave the rest of his to First Daughter and he had a banana. (And then First Daughter needed a banana as well, in addition to her chocolate.)
I think you could even decrease the cocoa a little; it was very rich. (Though we skipped the whipped cream. Perhaps that would soften the cocoa taste a little.)