Baby got back! 

Britney Spears made a rare red carpet appearance to help City of Hope honor Halston CEO Ben Malka with the Spirit of Life Award in L.A. October 10. Joined by Jason Trawick, 40, her fiance of 10 months, the X Factor judge looked statuesque in a backless, sequined Halston gown. A toned and tanned Spears, 30, completed her look with YSL shoes and Alexis Bittar jewelry.

PHOTOS: Britney Spears' dazzling music video looks

"Had a blast at the City of Hope charity gala!" the pop star tweeted. See more photos of Britney Spears at the event.

Though Spears turned heads at the event, she's much less glam in her everyday life. "I love my jeans and my sweats," she recently told ELLE. "I'm really just a tomboy at heart. So it's really hard for me to be like Kim Kardashian and be makeup- and hair-ready every time I go out of my house. I'm not a believer in that, you know?"

PHOTOS: Britney Spears, then and now

"On the other hand," she added, "when you do wear those sweats, you're like, 'Oh God, I should step it up a notch.'"

Spears has been back in the spotlight in recent months thanks to her high-profile gig on The X Factor; she joins Simon Cowell, 52, Demi Lovato, 20, and L.A. Reid, 56, at the judges' table.

VIDEO: Britney Spears enlists to help mentor X Factor contestants

"I feel like the world hasn't really gotten the chance to see her personality over the last couple of years, and now this is the perfect opportunity for people to really see the light inside of her just shine," Cowell recently said of the "I Wanna Go" singer. "She's very witty and funny and quirky, and I just have such a good time working with her."

This article originally appeared on Britney Spears Wears Sexy Backless Dress, Parties With Fiance Jason Trawick