Noel Fielding and Sandi Toksvig present the semi-final of the baking contest, which tests the four remaining bakers' skills with patisserie. There are only three places in next week's final, and this round of challenges will determine who does not make the cut. The signature dish requires a delicate dome and a perfect finish, while for the technical, the bakers must take croquembouche to the next level. Finally, for the showstopper, they must use all their skills to construct an edible display case.