Over-medicated, "bitchy," and sans-makeup: it's Jennifer Aniston like you've never seen her before.

In Cake, Aniston plays Claire, a wealthy L.A. woman struggling with the loss of her son. She soon joins a chronic pain support group, and becomes obsessed with the suicide of a cheery woman named Nina (Anna Kendrick), and the life she left behind. Clad in monochromatic, drapey loungewear, this is a far cry from Aniston's recent sexed-up (and phoned-in) roles in We're the Millers or Horrible Bosses. Instead, with a large scar on her face and a prescription pill cocktail always within reach, Claire does anything she can not to feel or remember life before her accident.

Like Sandra Bullock's character in Crash before her, Claire's only real relationship in the film is with her longtime housekeeper, Silvana (Adriana Barraza, of Babel fame). Devoid of real kinship, Claire forces Silvana to drive her around on errands while lying fully reclined in the passenger seat, even hitting Tijuana when she runs out of pills. She also drives away her husband (Chris Messina) and screws the gardener before befriending Nina's widower, Roy (a sad sack Sam Worthington). With dark circles under her eyes and no social graces, this is a woman so detached from reality it seems unlikely she has any exposure to sunlight. What will it take for her to wake up?

You can ask the same question about Aniston's career. Her paint-by-numbers rom-coms or sex comedies are wearing thin on her audience, and she knows it. Instead, with recent films like Life of Crime and Cake, she's trying to channel the spirit of her The Good Girl and Friends with Money days instead of The Bounty Hunter or Love Happens. With Cake, she succeeds in getting the dark comedy acclaim she's yearning for. Oscar buzz, however? She's not quite there yet.

At the TIFF red carpet premiere, Aniston told reporters how "freeing" it was to play a character who didn't care about what other people thought of her and greeted the world bare-faced.

Yes, Claire marks a great sardonic turn for the actress and the movie slowly reveals more about her backstory to make her more sympathetic. But, the character's selfishness provides limited rewards for the viewer, as the film's grey clouds and events muddy the depth of her possible redemption. As shocking as it is to see Aniston surrender control of her vanity, it does not outweigh the film's drastic tonal shifts. Let's remember, this script was once on the coveted Black List, but it's also directed by Daniel Barnz, who helmed 2011's Beastly. She may be great, but the film is hardly exceptional.

Buoyed by the strength of Aniston's comedic timing, Cake is still searching for a studio or distributor. Shot in just 25 days this spring, Cake marks Aniston's fourth time at TIFF with a film. After its Toronto screening last week, she laughed and said, "Let's hope the fourth time's a charm!" It could be, but it's one slice short of earning her the golden glory she craves.