It's crunch time for the bakers as biscuit week arrives, seeing them take on a 'slice and bake' signature, produce a classic chocolate Hobnob (other brands are available) in the technical and make their favourite mementos out of biscuit in the showstopper. Alison Hammond and Noel Fielding find out who will be top biscuit and who will crumble under the pressure, while Paul Hollywood and Prue Leith judge their efforts.