With the Feb. 1 closing of Macy’s River Room restaurant in downtown St. Paul, Immacolata Colosimo, 88, figured it was a good time to retire.

Bummer. The restaurant was a staple for shoppers and St. Paulites celebrating special occasions or holding business lunches. And there was no staple more hungrily craved than what Colosimo brought to the table. If her name isn’t familiar to you, her popovers might be.

For 40 years, Colosimo, called “Emy” by legions of fans, mixed together milk, eggs, flour, salt and unsalted butter to create light, hollow, sublime treats that became the restaurant’s signature offering.

“When she had a day off, the popovers weren’t the same,” said Colosimo’s daughter, Michelina Mariano, a former supervisor at the River Room, who cherished the decades she was able to work with her “role model” Italian immigrant mother.

How many popovers did Colosimo bake during her illustrious career?

“Millions and millions,” Colosimo could only guess, with a laugh. How many did she eat? Zero.

Colosimo, raised in Calabria in southern Italy, prefers her bread sturdy and crusty. But that didn’t stop her from attaining popover perfection, served up with whipped butter.

“If we’d run out, people would just get irate,” Mariano said. “I’ve had people walk out because they couldn’t get a popover.”

Colosimo moved to the United States at age 32, joining her Italian husband in St. Paul. Mariano recalls opening her lunchbox at school sheepishly every day, packed lovingly by Mama. In it, a fried green-pepper sandwich with provolone cheese on homemade bread.

“Nobody wanted to trade with me,” Mariano said with a laugh. “I couldn’t wait to run out so I could eat Wonder Bread. Now I understand.”

When Mariano and her two siblings were little, Colosimo was hired to demonstrate her embroidery and sewing skills at the downtown Dayton’s store, which later became Macy’s, and will close in March. She earned a princely sum of $300 for two weeks and went home to tell her husband that she was going to apply for a full-time position. He was skeptical. His wife spoke little English and didn’t drive.

What would she do?

Two days after submitting her application, Colosimo was hired as a part-timer in the kitchen. She made sandwiches — “they called them hoagies,” she said — then Scotch eggs, quiches, salads and from-scratch pastas and dressings, earning respect for her culinary skills and work ethic. She moved to full time, rarely taking a day off, or even a break.

One day in the early 1980s, her boss handed her a sheet of paper with a handwritten recipe. “Try this,” he said.

“I make lots of batter,” Colosimo recalled, seated in the cozy dining room of her home on St. Paul’s East Side, surrounded by family photos and several of her 40 bocce ball trophies.

She mixed 5 gallons of milk, flour, a tray of eggs, 6 pounds of butter and “lots” of salt, then poured it into a popover pan. The yield?

An oven fire.

“We kinda figure it out,” she said, “after a few little fires.”

Over time, she perfected the recipe, making 100 or more popovers daily, each batch rising slowly in the oven for 45 minutes. “People, they love it,” she said. “More than their food.”

Colosimo, a grandmother of seven and great-grandmother of three, shared her goodness far and wide. At the end of the day, she’d distribute leftover popovers to other workers, or give them to delighted fellow bus riders or neighbors.

On her last day at Macy’s, she made about 500 popovers for the overflow crowds. “I worked my butt off,” she said.

“That’s all we’d see,” confirmed Mariano, who recalled peeking into the kitchen to see her mother’s backside as she reached into the ovens.

“I’d pull ’em out of the oven,” Colosimo said, “and, right away, fill up another tray.”

She came out into the dining room to two standing ovations. “They make me cry,” she said. She signed menus with a Sharpie (“it was like a book-signing,” her daughter said) and customers asked to have their pictures taken with the Popover Princess.

Colosimo and Mariano will join other downtown Macy’s employees for a party March 7 to thank them for their service. Together, the mother-daughter team gave the company about 70 years.

Mariano, 50, who runs a Maplewood sandwich shop called Michelina’s Place, is figuring out her next move. Her mom is eager to get back to community volunteering, and enjoying her crusty bread, with a plate of spaghetti, whenever she likes.

But she’s proud of her popovers and will miss the many good years of bringing joy to customers.

“You work 40 years, it’s like your house,” Colosimo said. “But nothing stay forever. I started it, and I finished it.”

(To get your popover fix, here’s a link to the River Room’s popover recipe, adapted from “The Marshall Field’s Cookbook” by Steve Siegelman; Book Kitchen, $24.95. www.tinyurl.com/cqbnuyk)