Here is the problem with almost all of these attempts: there is no need to be a “pop quiz” where you have the answer, and the candidate is made to guess what you feel is right (even if you're wrong) and is walking in blind. This literally never happens in the real world - and if it does it means you’re getting fired. It’s just sadism you are pushing to make the in group people feel smarty pants and superior.

Tell the candidate up front what you want to talk about. Do it on a subject you dont know either so you are on even footing. Let them do research before the “quiz”. Since tokens are pretty cheap, ask them to build a working application and then discuss it with them.

This really isn't hard if you get off your imaginary high horse, and show candidates some basic respect.