How can I use my custom Class Type in the content browser?

I created a subclass of type UMaterial. Which will be my custom material. It shows up perfectly in the class viewer, but I can’t do anything with it. How can I actually “use” this new material in associated with some actor?

The goal:

I want to define a custom material class in C++, and make it available for use in the Editor. (Drag and Drop from the Content Browser preferably.)