Higher ed degree in curriculum and design?

I am interested in eventually pursuing a degree in curriculum and design (specifically in the area of mathematics). I have been doing research of doctoral degrees that would focus on the creation and implementation of curriculum but it seems as though there is not one specific degree to pursue. I see it fitting in to Educational theory and practice, Learning, Design, and Technology, as well as a doctorate in mathematics education.

Does anyone have experience in pursuing this type of higher degree or have any insight in doing so?

I would be greatly appreciated!