They will joined by singer Louise Redknapp, journalist John Simpson, EastEnders actress Maddy Hill and Prime Minister's wife Samantha Cameron.
Also taking part are comedians Jason Manford and Morgana Robinson, footballers Chris Kamara, Jermaine Jenas and David James, and TV presenter Victoria Coren-Mitchell.
Actors Alison Steadman and Ade Edmondson and former Shadow Chancellor Ed Balls round up the celebrity bakers in the charity special.
Mary Berry and Paul Hollywood will return as judges, while Jennifer Saunders, Ed Byrne, Sarah Millican and Mel Giedroyc will all host an episode each.
It will broadcast during Sport Relief on BBC next year.
For exclusive competitions and amazing prizes visit Reveal's Facebook page NOW!