Your company should have some sort of review process where they go over your performance and goals. These are usually the best places to express your passions

Your company should have some sort of review process where they go over your performance and goals. These are usually the best places to express your passions and career path. If they don't have that, you can always try and seek out one of the leadership team members and request a 1 on 1. If the leadership is reasonable, it would make sense to keep you coding and hire someone else that is a little more jr. to do the writing. The financial compensation might be a little trickier, but I think you should be able to negotiate that accordingly as well.