Wearing a neon-pink-and-lime-green, cut-out dress with a matching pink fluffy jacket, the star celebrated her 22nd birthday with a bash on Saturday at a Los Angeles nightclub.
The "Wrecking Ball" singer posted pictures of her taking a bite out of an oversized cake in the shape of a pizza.
Another Instagram snap from inside the party showed Cyrus and a friend riding on a pink phallic-shaped mechanical bull.
In addition to riding on the "bull," guests posed in a photo booth with blow-up dolls, drank Stillhouse cocktails and enjoyed a performance by Beacher's Madhouse, according to People magazine.
The magazine also reported that Cyrus' new beau, Patrick Schwarzenegger, dressed in a pilot's jumpsuit for the occasion, was by the singer's side throughout the night and even dug into the birthday cake with her.
Amid rumors the two are dating, Cyrus and Schwarzenegger were caught kissing at a USC vs. Berkeley football game earlier this month.