Crucially, shortbread contains no leavening agent, making it dense and durable—much like the TARDIS’s outer shell. One fan recipe blog writes: “Shortbread doesn’t rise. It just is. Like the Doctor.” In 2013, the BBC partnered with Walker’s Shortbread (Aberlour, Scotland) to produce a limited-edition tin featuring a collage of Doctors 1–11. The tin’s blue底色 mimicked the TARDIS exterior, and the biscuits inside were stamped with miniature Daleks, Cybermen, and the words “Allons-y!” (Tenth Doctor) and “Geronimo!” (Eleventh). Despite a retail price of £12.99, the tin sold out in 48 hours, later reselling on eBay for upwards of £80.