Course credit is not the same as professional certifications. You can apply past expertise/work to as many different certifications as you can manage.

Submitting previously graded work for a new course wastes your own time. It also wastes the professor's time, because they assigned that writing for you to develop a specific skill, and you're trying to not practice whatever they're trying to teach you.

If you have a perfectly matched essay to the assignment, you should talk to the professor about how the assignment can be adapted.