Is it possible to earn a PhD in mathematics with emphasis in teaching?
The "doctor of arts" degree was created in the 1960's to solve this problem.  It's like a PhD, but it doesn't require original research for the dissertation.  The goal is to prepare students for teaching careers that do not involve research.

Several universities in the U.S. offer DA degrees in mathematics, but they have never become popular.  Many people aren't even aware that such a degree exists, and those who know about it generally consider it inferior to a PhD.  Even institutions that do not expect their faculty to conduct any research at all often prefer to hire candidates who have some research experience in the past, in which case they would prefer a PhD to a DA.  (And many institutions require at least a little research to get tenure.)

For most people, getting a DA would be a bad idea: the time and effort required are comparable to a PhD, with worse career prospects.  However, there are some narrow circumstances in which it could make sense.  For example, some institutions (particularly high schools and some community colleges) don't require a doctorate at all but pay a higher salary to faculty with a terminal degree.  In that case, a DA might work just as well as a PhD.