Noel Fielding and Sandi Toksvig are returning to our screens for the double-bill, along with judges Paul Hollywood and Prue Leith.
With eight classic GBBO contestants returning over two episodes to create Christmas-themed confectionary, one episode will feature four contestants from the 2016's Bake Off.
Returning from the BBC's final season is Selasi Gbormittah, Val Stones, Benjamina Ebuehi, and Rav Bansal.
The second GBBO episode will feature child welfare office Sandy Docherty from 2015 and quarter finalist Paul Jagger from the same year.Related articles
BBC • CHANNEL 4Great British Bake Off Christmas special: Who will be returning to face Paul Hollywood?