The trip formed the basis of James Martin's Cakes of America, which sees him drive from Leesburg Virginia to Salem Massachussetts to discover the best cakes in the States.
"Travel broadens the mind and none more so than when you're a chef," he says, when we meet up in London fresh from the tour. "To learn more, you have to travel more. I looked at it and thought, I've done so many programmes in the UK - then it came to me about America and baking. With my pastry chef background, it was one of those things. I thought I could certainly do that. And then there was the driving side of it.
"I'd been to New York before so I knew how fascinating the food is there, but never really been anywhere else - I've been to Boston once, but I wanted to do that route all the way up. Connecticut, Philly, so many different places in terms of food.
"We just drew it on a map," he adds. "I'm surprised the car got round the whole lot, but it did."
After an average of every three miles, the team stopped to sample a cake. That's a lot of cake.
Don't believe us? The production crew kept a list for us - here goes...
3 x apple pie 3 x blueberry pie 2 x king cakes 74 x cupcakes 12 x butterfly cakes 10 x Washington cake slices 2 x Pimlico cakes 5 x peach cakes 4 x shoofly pies 5 x bags of pretzels 3 x key lime pies 25 x small cheesecakes 2 x large cheesecakes 1 x icebox cake 15 x slices of red velvet cake 2 x carrot cake 2 x honey cakes 35 x blueberry muffins 1 x rum cake 7 x small boston cream pies 25 x doughnuts 1 x bread cake 5 x bags of pretzels Oh, and 2 bottles of rum
Phew. So what were highlights of the trip? "The car would be one of them, the people and the places really - and food is among all that," says James. "The people really make this programme, they are fantastic. And you'll see places that you'll never have seen before. I'd never seen a pretzel factory before. I'd never seen a Washington cake before. Probably 99 per cent of things out there I'd never seen before.
"The way they make apple pie, the way they make brownies - I'd never seen it before so I'm assuming the professionals haven't either. I think people will learn a lot.
"I feel like if I'm learning from making a programme, then people will learn from watching it - it's like what we do on Saturday Kitchen. Otherwise you're preaching, and that's a different thing.
"The way the Americans look at food as a business is fascinating," he adds. "You can take an idea like a simple cake and turn it into a million pound a year business - no one else could do that in the world. The Americans have an open mind and an open culture when it comes to that and I hope it comes across on screen as well."
And James' favourite cake from the series? "I think the chocolate cake topped with meringue mushrooms is the most impressive one," he says. "The coffee and chestnut cake worked really well too, it was the first time I'd made it and just knew it was going to work. That one is my favourite."
Want to try the cakes for yourself? Take a look at James' brilliant cake recipes.