Well, according to wikipedia, in which metahumor redirects to meta-joke:

Meta-joke refers to three somewhat different, but related categories: "self-referential jokes", "jokes about jokes" (see meta-) also known as metahumor, and "joke templates".

Recursive humor would be a subclass of self-referential jokes, going by the definition for self-referential jokes as given by (what else?) Wikipedia.

This kind of meta-joke is a joke in which the joke itself, or rather a familiar class of jokes, is part of the joke.