Hi! I'm not sure about how close an interest has to be to yours, but from my own application process, I've had more positive communications and acceptances to programs with whom my interests closely align with the professor(s) I indicated. I also had kind of a niche research interest within the realm of education. One thing that I did to identify professors/programs is search for peer-reviewed articles on my research interest, look at the author(s) of the article and then google that author to see if they are currently a professor in any education PhD programs.