Can i submit a new common app essay after my old one was already submitted?

This probably sounds crazy, maybe insane, but I could email the admissions counselor and ask to change my personal essay entirely. I know its so late past the deadline, but I just wrote a far superior essay than the one I submitted, and would really like to change it. Is this possible? Should I even bother trying, or would I be laughed out of the admissions office?

No. You are stuck with the one you did, it would not bring you any favorable attention to try to change it.

Could i submit the essay I just wrote as a supplemental? Would it be viewed as annoying?

No, please don’t. By sending in additional essays, all you are suggesting is that your original essays were inadequate and you hope these new ones are better.

They don’t want extra essays.

Agree, it would be mistake. Your application is in. Your part is done. You are not given a re-do. Admission officers are super busy and have more than enough to read and would not appreciate getting extra essays at this point.