This Founder Wanted to Infuse a Marshmallow With Chocolate, for a Better S'More. He Had No Idea How Hard That Would Be.Michael Tierney, the founder of Stuffed Puffs, learned that sometimes the simplest problems are the most complicated ones to solve.

Michael Tierney was roasting s'mores when his million-dollar idea struck. "The cold piece of chocolate was just sliding around the graham cracker like a hockey puck on ice," he says. Annoyed, he shoved the chocolate directly into a marshmallow, where it melted harmoniously over the heat. Bingo.

Why hasn't someone commercialized this? he wondered. The answer would turn out to be far more complex than he had imagined.

At the time, Tierney was still in college at The Culinary Institute of America. He went on to work the kitchens of top-tier restaurants like Eleven Madison Park, but he couldn't shake his s'mores idea. "It was bugging me," he says, "every day." So three years later, he pursued it — and now, after a decade-long, winding path, hisStuffed Puffsare on pace to bring in $80 million in revenue.