After the 27-year-old singer was spotted on the film's U.K. set, the director shared a picture on Instagram to announce the news. In the snap, Will wished 'Eurovision's' latest star a very happy birthday.
"Y'all, Will Ferrell made me a cake," the birthday girl wrote on Instagram. "It looks completely professional and store-bought so I'm not at all suspicious that he baked it himself in all of his free time."
The ensemble cast of 'Eurovision' also includes Pierce Brosnan, Rachel McAdams, and Dan Stevens. In the film, Stevens and McAdams will play Icelandic musicians Lars Erickssong and Sigrit Ericksdottir, while Brosnan will star as Lars' father Erick Erickssong.
As for Demi's role, according to E-News, she will star as Katiana, "one of the best and most angelic singers in all of Iceland."