API Design Courses?

I'm struggling to find a good course that focuses mostly/soley on API Design.

What I find is a ton of courses on creating an API in language 'X'; that's not what I'm after, I understand the nuts-and-bolts of creating an API (primary C# Web-API if you're wondering). I'm after a course that covers the design of the API before you write any code.

BUT if you do know of an excellent API Design class that's also happens to be C#/Web-API focused, please send that along too!

Thanks!