What do you call just one biscotti?

A biscotto. There’s a little picayune, know-it-all tidbit you can use on friends and family, though they’ll certainly want to beat you to death with the nearest blunt object afterward. It’s right up there with, how’s that panino, Bill? Or, did you see that somebody spray-painted a gang sign on our garage wall? Such an ugly graffito. You just want to kill people for saying things like that. The reason of course, because they happen to be correct.