"I think I probably could have been a mechanical engineer in another life," Offit said, shrugging.
For now, she has settled on self-serve yogurt, a retail trend that debuted a few years ago on the West Coast and only recently became a foodie craze in Philadelphia with entries such as Whirled Peace in Manayunk and Kiwi in University City.
As of a year ago, the do-it-yourself "fro-yo" phenomenon had not reached Avalon, where Offit and husband Paul Offit, chief of infectious diseases at Children's Hospital of Philadelphia, own a summer house.
For much of the 22 years Bonnie Offit practiced medicine, she did it part time to be with her kids. Four years ago, the family bought the Avalon house as a second home; two years ago, Offit was "twiddling my thumbs" in it and decided she wanted to do some kind of work at the Shore on her days off from her medical practice in Haverford.
The self-serve fro-yo idea came from daughter Emily and a friend of hers who had a brother in college in California, where the concept was wowing consumers.
Offit did some research and opened her first yogurt shop last summer in Avalon, eschewing franchises.
"I didn't think at age 50 I was a franchise personality," she said. "I just wanted to learn it all from scratch." Friend Nancy Librett, a freelance marketing consultant, helped her with colors (purple, green and blue) and branding. They trademarked "soft surf" frozen yogurt, which is "just what the doctor ordered," according to the posters Librett and Offit designed for the stores.
Not brave enough to jettison her medical career at the start, last summer Offit commuted from Avalon to her pediatric practice two days a week, plus on-call weekends. The short-but-busy beach season yielded $70,000 in profit, with the average yogurt sale $5 to $8, depending on how generously customers piled on the yogurt (usually six to eight ounces) and the toppings (typically another two or three ounces).
In the fall, Offit sent a letter to her patients at CHOP Care Network giving notice of her intent to follow her entrepreneurial calling full time. Her last day of pediatric work was Jan. 2.
Charles Krafczek was thrilled. A custom-home builder based in Stone Harbor, he was hired by Offit to build out the Avalon store. They wound up partnering to buy the Stone Harbor property, a former art gallery on Second Avenue between 94th and 95th Streets and the largest of the three Bonnie's Toppings sites. Being the coffee connoisseur that Offit wasn't, Krafczek encouraged her to add coffee, pastry and sandwiches there, too.
But yogurt was the lure for Krafczek, who negotiated a 20 percent ownership stake in the Stone Harbor business after witnessing the response to the Avalon store.
"Seeing people flood in was quite remarkable," he recalled.
It taught Offit a valuable lesson about market penetration. "I saw very quickly you just have to be the first," she said.
That, Joe Staszak said, is why he abandoned his plan to open a self-serve frozen-yogurt store in Stone Harbor and, like Krafczek, partnered with Offit there instead.
In December, the ex-sports anchor at Fox29 had opened Sarandipity, the first self-serve fro-yo store in Exton Mall. The summer before, he had noticed Offit's store in Avalon and decided he had to open one in Stone Harbor, partly to take advantage of the compressed yet lucrative Shore season — Offit "can probably do in three to four months what I can do in a year," Staszak said.
Turns out a Realtor friend was already working with Offit to find her a place in Stone Harbor to expand. Staszak saw no sense in trying to compete with her in a town already brimming with frozen-dessert outlets, including Springer's Homemade Ice Cream and Cold Stone Creamery and Dairy Queen franchises. He and the Realtor, Craig Worton, became partners in the Stone Harbor store.
Offit paired with hotel executive Jerry Skot to finance her Cape May store, which also opened in May. Whether she'll open others is uncertain. She's considering another business model: licensing the Bonnie's Toppings name and serving as a consultant to others who want to open stores. Offit said she'd also like to find a way to keep some of her shops at the Shore open beyond the summer season, to keep people employed.
No longer seeing 30 patients a day has her feeling "refreshed," Offit said. Not that she's been able to totally leave medicine.
Jackie Borelli, one of her managers, recalled how Offit ran to the aid of a fainting customer and, in a separate incident, to a passerby who fell off a bicycle after colliding with a car. Customers who know of her medical background ask advice.
On a recent afternoon in Stone Harbor, Charlotte Kosmin couldn't care less about Offit's professional past or the protein content, live active cultures or calories in her YoCream yogurt.
Then again, Charlotte's only 19 months old. Her trip to Bonnie's Toppings was strictly about comfort.
"We had a doctor's appointment," said Charlotte's mother, Jeannie. "She got blood work. She wasn't happy about it."
As her daughter blissfully spooned cheesecake-flavored, nonfat, sugar-free frozen yogurt into her mouth, unfazed by the cold stuff that landed on her chin, Jeannie Kosmin stated the obvious: "She just loves this stuff."
Offit looked on in amusement — and with a healthy dose of empathy for what Charlotte had just endured during her doctor visit.
"Wouldn't it have been nice if I had the machines in my office?" she asked. "All we had was stickers."
Contact Diane Mastrull at 215-854-2466, email@example.com or follow @mastrud on Twitter.