Biscuit

 was a baked flour-based food often served with tea. (TV: The Invasion, Victory of the Daleks, The Last Precint)

Types of biscuits

 * The Second Doctor once asked for a patty cake biscuit with his tea. (TV: The Invasion)
 * Kirsty McLaren offered a wheat biscuit to Polly Wright, who mistaked it for a dog biscuit.
 * Sailors often ate hardtack which they did not like. (TV: Enlightenment)
 * The Best company sold biscuits. (TV: Liberation)
 * The Seventh Doctor's favourite biscuits were chocolate HobNobs.
 * Eleventh Doctor hated ginger biscuits. (PROSE: Dead of Winter)
 * The Eleventh Doctor was very fond of Jammie Dodger biscuits. (TV: Victory of the Daleks)