To my mind, perhaps the most unusual example of a well-known genre author crossing over into YA turf is a long out-of-print relic called “Nick and the Glimmung,” written by none other than Philip K. Dick. Published in 1988, six years after his death, and never released in the United States, “Nick and the Glimmung” has the gentle pacing and simplified vocabulary of a young-adult novel, but its sensibility and subject matter are unmistakably Dickian.
Gentle pacing? Simplified vocabulary? Huh? (Hat tip to Carrie!)