For the very first time on Bake Off, it's Vegan week. Prue and Paul have set three very different challenges to test the remaining bakers. A savoury pastry Signature, with no butter involved. A cracking Technical, with a very unusual ingredient. And finally, a spectacular Showstopper that, in the heat of the tent, threatens to lead to catastrophe. Who will keep their cool and win star baker? And ...