How many letters does the top answer for “author of jerusalem” have?

The most common answer is blake (5 letters).

Crossword clue: author of jerusalem

2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

blake 5 letters wd-fact-v3

visionary British poet and painter (1757-1827)

lagerlof 8 letters wd-fact-v3

author of eichmann in jerusalem 67% similar → arendt

author of jerusalem delivered 67% similar → tasso

author of 1q84 50% similar → murakami

author of 2666 50% similar → bolano

author of 4 3 2 1 50% similar → auster

author of q11368 50% similar → kernighan, ritchie

author of q13415681 50% similar → hamill

author of q134773 50% similar → zemeckis