Twelve of the country's best amateur bakers take part in the second series of `The Great British Bake Off'. In the first round, the bakers are challenged to make 24 decorated cupcakes in two hours and the stress soon shows. Next, they face a technical challenge - featuring a coffee and walnut Battenburg cake from one of Mary Berry's recipes - and finally, they have to make and bake a tiered showstopper cake.