The Bake Off begins with Cake Week, and sees the bakers take on a fruity signature challenge.

It's week two, and the sandwich biscuit signature challenge sees bakers trying to blend biscuit and filling. There's a technical task set by Paul Hollywood that no one has tried before. And a final showstopper challenge that takes the biscuit and is literally game changing. Paul and Prue Leith cast a critical eye over the contestants' efforts, while new hosts Sandi Toksvig and Noel Fielding settle into their roles. As ever, it remains to be seen which of the unlucky bakers will be shown the door.

It's Bread Week and the ten remaining bakers have a lot to prove to Paul Hollywood and Prue Leith. This time they've been set three tough challenges: a teacake signature, where they must rise to the challenge; a two-tiered technical that's back to basics; and the most ambitious sculpture showstopper ever set in Bread Week. Only one can claim star baker; while another will leave the tent for good.

Nine bakers remain and for the first time it's caramel week. Prue Leith and Paul Hollywood have set the contestants three sticky challenges - a super sweet signature with a rich teatime favourite, a double Dutch technical, and a caramel showstopper. The three tasks will result in one star baker, while another will leave the tent for good. Sandi Toksvig and Noel Fielding lend a hand with pep talks and shoulders to cry on.

It's pudding week and the signature challenge is a steamed favourite. There's a technical challenge where timing is everything and a multi-layered showstopper that's not to be trifled with. Which bakers will impress Prue Leith and Paul Hollywood enough to keep their place in the tent? And which of the eight remaining bakers will be heading home? Noel Fielding and Sandi Toksvig are with the contestants every step of the way, and during a break from the action, Sandi returns to her old haunt, Cambridge University, to discover the history of the college pudding.

In week six there's a savoury signature, where contestants must impress judges Paul Hollywood and Prue Leith with style and substance. There's also a multi-layered technical, and an ambitious final challenge, in which the bakers make a traditional pie. Sandi Toksvig and Noel Fielding are with the contestants every step of the way, ready with a pertinent pep talk or just a sympathetic shoulder to cry on. Also, Sandi heads abroad to discover how some unusual habits have inspired a classic pastry treat.

The amateur cooks take part in Italian week, which culminates in a fiddly showstopper in the hottest temperatures ever recorded in the tent. Before that, under the ever watchful gaze of judges Paul Hollywood and Prue Leith, the contestants dish up a Sicilian signature that gets them all hot under the collar and a deceptively tricky technical. Noel Fielding and Sandi Toksvig are on hand to keep the bakers in line as the pressure of reaching the final stages of the competition intensifies

The remaining five bakers step back in time for Forgotten Bakes Week, facing the test of baking with unfamiliar recipes, with places in the semi-final at stake. They start with a sweet and savoury signature challenge, before Prue Leith sets a boozy technical and, for their final challenge, the bakers must produce an elaborate sponge showstopper that once graced the dining tables of high society. Sandi Toksvig and Noel Fielding are on hand to help the bakers calm their nerves.

It's the semi-final, and the four remaining bakers must set to work on producing 24 exquisite choux buns. Prue Leith has set a complex technical for her first semi-final that leaves everyone stumped. And there's a meringue sculpture showstopper where the bakers mustn't crack under pressure. Noel Fielding and Sandi Toksvig present, while Paul Hollywood passes judgement alongside Prue.

Twelve bakers started, just three remain. Who will succeed with the demanding final challenges, including a high-end patisserie showstopper, to be crowned winner of The Great British Bake Off 2017?