-- ABC News' CAROLYN DURAND reports:
The company essentially takes your favorite selfie or personal photo and uses a complicated technological process to customize it atop a marshmallow to create a unique sweet treat that they call "gastro magic"
"We've had to develop the technology to enable us to do it on the scale that we're doing," Middleton, 27, told ABC News' Amy Robach in an interview this week in New York City. "But it kind of clicked into creating something that people seem to respond to really well."
It was a process until Middleton and his business partner, Andy Bell, came up with the concept they thought might work.
"We thought, 'Let's bring a modern era confection in the modern era,'" Middleton said. "After a few months of brainstorming, sampling and trying different things, we came up with photo marshmallows."
"I am the younger brother of Pippa, of Catherine so, for me, I very much feel like I'm my own person," Middleton said. "And I suppose there is this 'the-brother-of' side to me but, actually, it doesn't change who I am.
"I'm still very much James and people who know me and who have met me in the past will always say that I'm very much the same person that I was sort of prior to and after," he said, referring to the 2011 nuptials of Kate Middleton and Prince William that formally introduced the world to the Middleton family.
The hardworking, U.K.-based entrepreneur is obsessed with every facet of his company, routinely putting in 14-hour days. He doesn't leave details to others. He is a man on a mission.
For all his hard work, Middleton, who holds the title "Wonka-in-Chief" at Boomf, does seem to have a hit on his hand.
Business-partner Bell, who holds the title "Chief Edible Officer,” describes the demand for the marshmallows in the less than one year since the company launched.
"We're going 10 months now and I think we've sold nearly a million pounds worth of marshmallow, which is like eight tons of marshmallows," Bell told ABC News' Robach.
Middleton on Obstacles Faced and His Family's Support
James credits his family, which owns a party-planning business of their own, with giving him the support and initiative to pursue his dreams.
"They'd just look at me and say, 'OK, go for it, then,'" Middleton said of his parents, Carole and Michael Middleton. "My parents are entrepreneurs and so there's a lot of advice and things I've learned along the way from them.
"So I think they see a bit of my vision and a bit of my sort of experimenting but also they just sort of think, 'Marshmallows? Really?’" he said. "They're very impressed with the success of the company so far and support me all the way with it."
Indeed, it was not an easy road getting there. James Middleton suffers from dyslexia but says he believes that hurdle has helped channel his creative talents.
He went to Edinburgh University in the U.K. but, after a year, dropped out hoping to pursue his dreams. "I feel that dyslexia actually has allowed me to be creative," he said.
He describes his being "terrified” of the dyslexia and trying to read in front of the billions watching the wedding around the world so he memorized the passage and used cues to help him overcome his fear.
While Middleton is now in New York City to promote Boomf, this is not his first visit to the United States this year. He and his sister Pippa, 31, completed a cross-country bicycle race to raise money for charity in late spring.
"Fourteen states we went through [and] three different time zones," Middleton said. "And it was one of the most wonderful experiences me and Pippa have ever taken part in.
Sounds like James Middleton's business will see him spending more time in the United States.