Ex-Kardashian Nanny Shopping Tell-All Book -- Trashes the Kids

The help is turning on the Kardashian clan ... TMZ has learned a former family nanny is shopping a tell-all book about her time with the K-squad before they were famous ... and it's clear she HATED some of the kids.

Sources tell us ... the woman behind the book, Pam Behan, served as a nanny, personal assistant and cook for Bruce and Kris Jenner for years ... and spent all sorts of time with the Kardashian girls AND the Jenner boys, Brody and Brandon.

We're told ... in the book, Pam makes it clear -- she couldn't stand Bruce's sons ... calling the two kids, "extremely spoiled and disrespectful."

In the book, we're told Pam also claims she almost lost her job after slapping Brandon one day.

As for the Kardashians -- we're told Pam describes her relationship with Kris as a "love/hate" thing ... but she seems fond of Bruce, claiming he helped her avoid prosecution when she was busted for DUI a while back.

We're told Pam also promises to reveal some "intimate details" about Kourtney and Kim -- surprising, because we're told the girls were very fond of her.