It's semi-final time and the tension is palpable as the bakers begin Patisserie Week. The semi-finalists are challenged to make signature baklava - two different types of any flavour they like, but with the crisp flaky layers of perfectly pulled filo pastry. Next up is the penultimate technical challenge of the series, which sees the bakers make layers of a different kind. The German schichttorte is a cake cooked in stages under the grill to create 20 layers of different-coloured sponge. It is based upon the German baumkuchen which is baked on a rotisserie and is one of the trickiest German cakes. The showstopper challenge raises the bar even higher. The final four bakers must bake nonstop to create two elegant entremets. They are asked to show as many skills and techniques as they can possibly pack in - this is their last chance to fight for their place in the final. On your marks, get set... bake!