Central Bakery in Tiverton, Rhode Island, makes only one thing: bolos lêvedos. But brothers Paul and David Lopes believe this laser focus is the key to their 30-plus years of success.

“My mom and dad came to the United States and realized no one was making the muffins. In 1974, they started making them in their garage, then opened up their first bakery,” Paul says. The muffins were based on the recipe Lopes's grandmother used back on São Miguel, an island in the Azores.

Business took off, thanks to word of mouth. “One of my dad's first big hits was on Cape Cod [in the late 1970s],” Paul says. Vacationing New Yorkers brought word of the muffins back to the city, starting a sales boom.

Paul credits the company's evolution to his customers. “In Portugal, the only thing they used the muffins for was breakfast. But the American public got really creative,” Paul says. “Now, the number one use for this product is a hamburger bun.” Central Bakery, an exclusively wholesale operation today, supplies Madison Square Garden and Yankee Stadium, among others.

Sticking to a single product confounds some customers. “I'll talk to a retailer and he'll say, ‘What else do you have?’ and I'll say, ‘This is it,’ and he'll say, ‘You make just one product since 1974?’ But it's keeping our doors open.”

That extreme focus extends to the recipe and process, too. The brothers keep the specifics top secret. “We've tried to adapt, but it's not the same.”