The former Friends star has been widely praised for her harrowing and at times darkly comedic performance as a chronic pain sufferer who becomes fascinated by the suicide of another woman in her support group.
Her powerful portrayal has already earned her prestigious nominations including 'Best Actress in a Drama' at the Golden Globe Awards, and there has been talk of an Academy Award nod when those are announced soon.
As well as her acting, Jen's bold decision to go make-up free for the movie has also been widely discussed.
We're used to seeing her with a bronzed glow and swishing her luscious locks on the red carpet, but in Cake she's practically unrecognisable as the dowdy Claire Bennett, who shuns make-up and grooming.
She also has scars across her body as a result of a car crash.
Jen said recently that going make-up free on film was "so fabulous—so dreamy and empowering and liberating. The only time I had to sit in the makeup chair was just for the scars."
Cake arrives in UK cinemas on 20 February.
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