Sue Perkins and Mel Giedroyc present as the remaining four bakers take a deep breath and head into the semi-final of the nation's favourite baking contest. However, there's no time to marvel at how far they've come - it's Patisserie Week, and they will need to demonstrate that they have skills worthy enough to see them through to this year's final. The bakers are challenged to make a signature baklava - two types of any flavour they like, before the technical challenge demands they knock up a German Schichttorte, a cake cooked in stages under the grill to create 20 layers of different coloured sponge. Finally, the showstopper sees the semi-finalists baking non-stop to create two entremets in which they should demonstrate as many personal skills and techniques as they can