The Great Celebrity Bake Off for Stand Up to Cancer preview: 5 things to look out for

However, the episode has taken on an added dimension after it was revealed that former BBC Breakfast star and Celebrity Bake Off contestant Bill Turnbull has been diagnosed with prostate cancer.

The broadcaster spoke to former colleague Sian Williams about his diagnosis in a moving Radio Times interview, where he said he wanted to make sure “all the days count” and urged other men to make sure they have regular check-ups.

Turnbull explained that he was diagnosed as he was filming the Bake Off Stand Up to Cancer special. "When I was making my cupcakes, I had the disease and didn't know it," he said. The Channel 4 celebrity baking show will air a filmed update about Bill at the end of the programme.

Bill's sad news inevitably casts a shadow over the episode, but Bake Off still delivers plenty of light-hearted moments, from half-baked crepes to underdone biscuits, all to raise money for the most worthy of causes (full details of how to donate are below).

Here are some of the things to look out for in Tuesday’s first episode.

Martin Kemp reckons he’s got cupcakes down pat

For the signature challenge the celebrities are tasked with delivering 12 iced, decorated, identical cupcakes to judges Prue Leith and Paul Hollywood.

Former Spandau Ballet and EastEnders star Martin has more than a dash of smugness as he explains that he used to make cupcakes with his kids all the time after they came home from school.

His design is elaborate and his ambition grand for Kemp’s Special Cupcakes (this is what he genuinely decided to call them - although thankfully he doesn't elaborate on what makes them 'Special').

Anyway, in true Bake Off style, we can all see where this is going can’t we?

“Oh for fu...I’ve put the wrong stuff in the wrong thing,” an exacerbated Martin says, before ending up on his knees, explaining that he’s had an “absolute mare” and that he’s “never going to live this down”.

All this over a few cupcakes.

Kemp's disaster is just the beginning

It’s not just Martin who has a disaster. Not for the first time in Bake Off history, someone's creation enjoys a meeting with the carpet, Sandi Toksvig gets a fire extinguisher at the ready for Harry Hill and something horrendous happens to Tony Hadley. But don't worry, he's only in biscuit form. But special mention has to go to the next contestant...

Roisin Conaty is a bloody awful baker

Did comedian Roisin Conaty actually know what a kitchen actually was before she stepped into the tent? Her utter lack of baking ability is stupendous.

Cakes go in the freezer, measurements are disregarded, she asks what flambé means and makes a mixture that’s supposed to be smooth look like lumpy porridge. On top of all that, she does a Richard Blackwood and asks, “What’s zest?”

Undeterred, she staunchly claims that she might be the “best baker who ever entered the tent”.

Mary Berry gets a shout out

Is this…allowed? Surely it’s some sort of sacrilege to utter Bezza’s name in the tent post-2016?

That doesn’t stop Harry, who takes a pop at Mary Berry by joking that her birth certificate would be written on vellum – which is basically a proper old parchment paper used to write stuff like the Magna Carta on.

Paul sniggers. A bit too much if you ask us.

Harry Hill’s showstopper is hilarious

The Showstopper Challenge tasks the celebrities with making a 3D biscuit scene of the best day of their lives. So, of course, Harry decides to recreate ‘the day I went on holiday with Camilla Parker Bowles’. There’s a proper backstory involving a talking turtle and everything. Paul clearly doesn’t know what to make of this, as Harry proudly proclaims: "That’s a horse on a surfboard”.

The Great Celebrity Bake Off for Stand Up to Cancer starts at 8pm on Tuesday 6th March on Channel 4