Jo, Judi Love, Carol Vorderman and Iain Stirling dunk themselves into Biscuit Week. Which bakers got stuck into the marshmallow Signature, and who made a meal out of the illusion Showstopper?
| Name | Type | Role | |
|---|---|---|---|
| Iain Stirling | Guest Star | ||
| Judi Love | Guest Star | ||
| Carol Vorderman | Guest Star | ||
| Martin Lord | Director |