The True singer hit the studio with Zilli, who represented Italy in the Eurovision Song Contest in 2012, earlier this year (15) as he recorded tracks for his first holiday release, The Christmas Album.
The original has become an evergreen Christmas hit after first making the festive charts in 1987. It has also been covered by KT Tunstall and Ed Harcourt, Christy Moore and Ronan Keating and Maire Brennan, among others.
Hadley's new solo album also features the Spandau Ballet star's take on Keane's Somewhere Only We Know, Mud's Lonely This Christmas and Greg Lake's I Believe in Father Christmas.
The singer is currently competing in the 2015 series of the U.K.'s jungle-based reality TV show I'm A Celebrity... Get Me Out of Here!.