Noel Fielding: "The judges would like you to make twelve biscuit bars. You can use any biscuit you like, but they mus be identical in every way."

Alison Hammond: "Exactly. Now the judges are looking for a bar shaped biscuit which is either topped or sandwiched with a lovely, delicious filling."

Behind the Scenes

Paul Hollywood: "We're asking the celebrity bakers to make twelve biscuit bars for their signature bake. It could be one biscuit, maybe covered in chocolate, but it could be a sandwich biscuit. You want a decent snap. They need to watch the biscuit to make sure it's getting baked properly. Over baked, it'll be bitter, underbaked, it'll be raw. You've got to find that sweet spot."

Prue Leith: "I never have high expectations of celebrity bakers. They don't really come here because they're great bakers. They do it because they want to support, stand up to cancer."