Isn't love changing David Mitchell? (8)
I believe the answer is:
novelist
'david mitchell?' is the definition.
(novelist David Mitchell is an example)
'isn't love changing' is the wordplay.
'changing' is an anagram indicator.
'isnt'+'love'='isntlove'
'isntlove' anagrammed gives 'NOVELIST'.
(Other definitions for novelist that I've seen before include "Writer of fiction books" , "Spark produced, perhaps" , "Author" , "Book writer" , "James was one" .)