This was an idea for a name that I really liked when I was younger. I thought it was such a pretty-sounding and pretty-looking word. The nickname "Cay" seemed like a more interesting version of "Kay", which has a lovely sort of 1940's energy to it. Yes, it's a pepper, but it's also a place name (the capital of French Guiana). I recognized that it was a bit silly, but that was also part of its charm.
What would you think if you met someone named Cayenne? Do you think it's better suited to a book character, or a pet?
Also, how would you pronounce it? I've heard cayenne said both like "K.N." and like "kye-ann".