WRT to Oreo Coke, the best description is Vanilla Coke with a dark chocolate flavor, but somehow not like the chocolate a European might imagine.

I found out recently that Oreo is in fact made with real cocoa; I find this surprising and still somewhat hard to believe.

The drink’s unique combination of flavors somehow made the whole experience less cloying than a typical zero sugar coke. And also, mysteriously, it was quite satiating, almost like I had eaten actual cookies. Except not, because any American can tell you that Oreo has negative satiation - you can eat an Oreo from a state of not being hungry at all, then discover you have eaten a whole Family Size pack.