Party extraordinaire Paris Hilton jumped out of a cake at her boyfriend’s birthday.

The blonde socialite threw the surprise party for Doug Reinhardt at her Beverly Hills mansion last Saturday and wore a sexy hot pink outfit and a black diamond mask as she burst out of the giant-sized sweet treat.

A source revealed, “Paris went all out for her man’s birthday. No expense was spared. He had no idea about the party and was so happy.”

Paris was so keen to impress The Hills star, whom she reunited with in the summer when he whisked her away on a romantic break to Fiji, she organized for rap group Three 6 Mafia and hip-hop star Ya Boy to perform for partygoers.

Guests including Hollywood beauties Hayden Panettiere and Kristanna Loken, partied until 3am at the nightclub Paris has built in her home, while home videos of the couple were screened throughout the mansion.