Revenge is a dish served ice-cold for SHANIA TWAIN as the jilted beauty reveals all in explosive new tell-all!!

The 45-year-old Grammy winner is paying back her cheating ex-husband Robert "Mutt" Lange by writing a memoir about losing him to her pal and former house manager, Marie-Anne Thiebaud.

"Shania is going to have the last laugh," a longtime pal told the ENQUIRER.

"She’s never bared her soul publicly, but she intends to finally set the record straight. She kept a diary for years and plans to spill all the sordid details of Mutt’s affair —   And her emotional showdown with Marie-Anne."

Married for 14 years, Shania and songwriter/music producer Mutt split in 2008. .

Despite Shania’s high-profile career, the couple lived a reclusive life, as Mutt maintained a Svengali-like grip on her, the source said.

"Her self-esteem suffered, and she grappled with severe depression and came close to a breakdown."

The book – to be published by Simon & Schuster – will reveal the Canadian-born thrush’s dirt-poor upbringing, the tragic death of her parents and her against-all-odds rise to superstardom.

For all the details pick up the new ENQUIRER – on sale now.