Pretty much the only reason "ravioli code" has survived as a phrase is because programmers have an innate sense of humor. Try as I might - and believe me, I've tried - it's really hard to come up with an example of object oriented code that was both (a) packaged such that it was really hard to navigate in the same meta-sense that "spaghetti code" is hard to navigate, and (b) reflected a frequent anti-pattern in coding practice.
The best example of "ravioli code" I can come up with is a multitude of classes, each tightly packaged, but where it's really hard to dig out where the main flow of execution is. Neural network applications might exhibit this, but that's sort of the point. A more mundane example would be UI code that is very heavily event-oriented, but again, it's hard to go overboard with that - if anything, most UI code isn't event-driven enough.