Britney Spears gets three-tier surprise birthday cake at 'iHeartRadio Jingle Ball'

Britney Spears, who recently turned 35, received a birthday surprise at KIIS-FM's 'iHeartRadio Jingle Ball 2016' concert at in Los Angeles.

The 35-year-old songstress was performing a bunch of her hit songs, including 'Toxic', 'Stronger' and 'I'm a Slave 4 U' when Ryan Seacrest came out on stage and led the audience to sing 'Happy Birthday' along with a three-tier cake with black fondant, pink frosting, pink roses and sparkling embellishments, reports E! Online.

Prior to this surprise, Spears closed her set with 'Slumber Party' with special guest Tinashe.

"Guess what? It's my birthday. You guys ready for a slumber party?" the 'Make Me' singer told the crowd before giving a well-versed performance with the dance crew.

Other performers included Fifth Harmony, Alessia Cara, Bruno Mars, Diplo, Meghan Trainor and Justin Bieber, who closed out the show.

Celebs spotted in the crowd included Lance Bass and husband Michael Turchin, 'Grey's Anatomy' actress Camilla Luddington, 'Bachelor in Paradise' couple Josh Murray and Amanda Stanton, their co-stars Nick Viall, Jared Haibon and twins Emily Ferguson and Haley Ferguson and 'Dancing with the Stars' pro Witney Carson.