Does this sounds right? I’m taking about a book I like by an author I like!
One of my favorite books by one of my favorite authors..
One of my favorite books by one of my favorite author (this one sounds weird but idk)
Simple calculation - when you say one of something means you have more than one of that thing!
One of my friends ...
Obviously, it is one of many, so,
one of my favorite authors
In certain cases, yes, you can use double 'one of...' as in your example -
This is one of my favorite books by one of my favorite authors
Without 's,' it would be ungrammatical.
No. "One of" takes a list, so in this case it means "one author out of a list of authors". So it's plural.
If it would not be plural, that is, if you had only one favourite author, it would not have been a list and you could not have said "one of". Rather just "... by my favourite author".