Just looked at this on DFTMC and the composer credits say that Smokey wrote this with Mary Wells.
Knowing Mary wrote her very first single, Bye Bye Baby, makes me wonder what else Mary had a hand in whilst at Motown. Bye Bye Baby is a great song and I am surprised that no other Motown women had a go at it. Mind you, they would have to be really good to top Mary's original!
SWI