Using everything that they have learned so far, the final three chocolatiers embark on the ultimate chocolate challenge. The battle begins with a brutal knock-out round, in which they must create three different versions of their unique signature chocolate bar. After being whittled down to two, they create a prototype bar that can be developed and manufactured by a major company - having first been scrutinised by panel of elite supertasters and members of a chocolate-loving focus group. Last in the series.