Hmm... Let's see...

Oh, functions can't return arrays in C. That would be a pointer. Well, that makes it easier.

    double **(**(*)(char *))(int)

It did take a couple minutes, but I just woke up. Also, idiomatically there would be a typedef:

    typedef double **A(int);
    typedef A **B(char *);
    B *

That took a few seconds to write.