Bawdy writer redrafted serial, penning a book (8)
I believe the answer is:
rabelais
'bawdy writer' is the definition.
(I've seen this before)
'redrafted serial penning a book' is the wordplay.
'redrafted' is an anagram indicator (to redraft something is to improve or rewrite it).
'penning' is an insertion indicator.
'book' becomes 'b'.
'serial' with letters rearranged gives 'relais'.
'a'+'b'='ab'
'relais' placed around 'ab' is 'RABELAIS'.
(Other definitions for rabelais that I've seen before include "French writer" , "Sixteenth century French satirical author" , "16th-century French satirist, noted for earthy humour" , "Creator of Gargantua" , "Francois ......., 16th century French satirist - sort of base liar" .)