CORNERED by the press in a back room of McGhee's family bakers, David Cameron had no choice but to answer the question.
What, pray tell, was his favourite cake? The answer perfectly illustrates his political acumen and suitability to lead. Was he swayed by the aroma of flour and sugar to fall for the firm's French Fancy or Pink Tart and slip into a trap of barbed headlines?
Of course not; like his character in When Boris Met Dave, the recent Channel 4 docu-drama that paired his appearance with Sade's Smooth Operator, Mr Cameron plumped for the oatcake, the healthiest, most worthy, not to mention Scottish of baked goods.
"I'm not just saying that because I'm in Scotland," he insisted, not that we believed him. "I find them very good for filling you up if you are hungry." Hmm, but so is Eton Mess.
In fairness, Mr Cameron had already decided to trip himself up. Seconds after climbing out the car, he was briefly undone by the factory gate's runners. Resplendent in revolutionary red, Annabel Goldie almost had to catch him.
The Conservative leader was in Glasgow's Springburn to support Ruth Davidson, the party's candidate in the forthcoming Glasgow North East by-election, but decided against striding the streets and introducing the public to their first old Etonian.
Instead, he enjoyed a guided tour of McGhee's family bakers, the firm behind both the city's famous "crispy roll" and potato scones and Scotch pies.
While one spin-doctor may have arched an eyebrow about the appropriateness of such a venue given the constituency has the poorest health and diet in Britain, Mr Cameron was untroubled when asked.
"Funnily enough, they were just telling me about their plans to introduce low-fat Scotch pies and one of the questions I asked was how are people's tastes changing, and actually people are making healthier choices and so this bakery is responding to that." Healthy Scotch pies – isn't that like "clean" coal?
The party progressed past the ovens. "This is an oven", said Gordon McGhee, the managing director. "And what is that … um," said David Cameron, thankfully shutting down before saying "for?"
While the visit of Mr Cameron to one of the poorest parts of Britain could have offered the opportunity to move from the question of inherited wealth to inherited poverty, the Tory leader's trip was all too brief.
When asked why he visited given the party's dire electoral performance in Scotland, he replied: "I believe in campaigning in every by-election where there is a Conservative candidate standing, I think it is important, and in Ruth Davidson we have got a first-class candidate. She is really putting up a good fight and I think Labour has failed the people of Glasgow.
"I'm the first party leader to walk the streets. That is what party leaders should do."
The Scotsman said: "But you're not actually walking the streets." He replied: "I hit the streets when I came in – I nearly fell over."
The SNP, he explained, was wrong to discuss the inevitability of independence and it would find no allies in No10 if the Conservative Party won the general election.
"If Alex Salmond thinks a Conservative government is going to help him achieve his dream, he has got another think coming."
Then he was away, striding past the table laden with rolls, cakes and tarts – an abstinent man in search of a Tory rival and, of course, an oatcake.
THE TORY LEADER VS THE SPRINGBURN MAN
Born: London, to a stockbroker and a baronet's daughter.
School: Eton College.
University: Oxford, gaining a degree in Philosophy, Politics and Economics (first class).
Social Life: The Bullingdon Club, whose members have a reputation for damaging property while inebriated.
Wealth: The Sunday Times Rich List puts the combined wealth of David and Samantha Cameron at 30m-plus.
Born: Springburn Man was born into one of the poorest constituencies in Britain. He is the son of a single mother.
School: He left with no qualifications, the rate of this occurring is 300 per cent above the Scottish average.
University: Er, no.
Employed: No. Unemployment in Springburn is 140 per cent over the Scottish average.
Social Life: Also likes to get drunk (when he can afford it).
Future: He has a 50 per cent chance of reaching age 50.