A Bourbon biscuit was a type of biscuit.
The Eleventh Doctor disliked bourbon biscuits. Amelia Earhart enjoyed them, however. When the Thirteenth Doctor voiced her own dislike for them, cross at anyone who might disagree, whilst remembering her time as the Eleventh Doctor, Yasmin Khan felt that the Doctor was acting quite unlike herself. (PROSE: Chasing the Dawn)
Nurse Bledsoe took Bourbons from one of her patients. (AUDIO: Ashenden)