There are certain sets of procedures that need to be followed to become a professor in Finance or any other field.
Your best available option is to apply for a professor in the university where you have completed your post-graduation. If you were acquainted with the graduate committee, they can recommend you as an assistant professor. It would be better if you start working in the industry related to Financial services as a fresher and gain some work experience. And simultaneously, you can be a visiting lecturer in the colleges that offer MBA Programs.