The most popular dessert in Dodgers history is back, and cinnamon is the secret ingredient.

The Cool-A-Coo, the ice cream sandwich that accompanied strikeouts by Fernando Valenzuela and home runs by Mike Piazza, returns to Dodger Stadium on Thursday.

When Stan Kasten took over as the Dodgers’ president May 1, he put the Cool-A-Coo revival at the top of his to-do list. He figured it would take a few weeks, not an entire summer.

“We had to put Humpty Dumpty back together,” Kasten said.

Leo Politis, the South El Monte dairyman who made the original Cool-A-Coos, had sold his company — and with it the Cool-A-Coo trademark. Sweety Novelty, the Monterey Park company that had acquired the trademark, did not make Cool-A-Coos.

Levy Restaurants, the Dodger Stadium concessionaire, got a recipe. The basics had not changed: vanilla ice cream wedged between oatmeal cookies and dipped in chocolate. But in the 14 years since the Cool-A-Coo last appeared at Dodger Stadium, the American palate had changed.

So the vanilla ice cream is not as sweet now, and more dense, according to Jason Tingley, Levy’s executive chef at Dodger Stadium. Levy staffers tried a few prototypes, then prepared the tastiest version for Kasten.

He loved it. Then he asked a few employees who had worked at Dodger Stadium long enough to have eaten the original Cool-A-Coo for their opinions.

“Like it,” they said. “This isn’t it.”

The cinnamon was missing — from the cookies, it turned out, and not from the ice cream.

“It’s the little hidden secret,” said Brent Sloan, Levy’s director of operations at Dodger Stadium.

The perfection of the recipe was the first step, not the last. The Dodgers had to negotiate a contract with Sweety Novelty to manufacture the Cool-A-Coo and renegotiate deals with ice cream vendors who would now have a competitor at the concession stand.

Levy had to work with Sweety on logistics — including the printing of the original Cool-A-Coo logo on each label — and with the Dodger Stadium staff to prepare for the introduction of a popular concession item in the middle of a season.

Sloan said the ice cream sandwich would sell for $5.75 at the concession stand and $6 from roving vendors.

The Dodgers charge $6.75 for a bucket of “Dibs,” the bite-sized frozen treats that Sloan says are the stadium’s top-selling ice cream item. Sloan said he did not consider the price of the Cool-A-Coo overly high.

“We looked at our other ice cream items,” he said. “This is one of the lowest [prices].”

Kasten said he is pleased to remove the Cool-A-Coo from his weekly to-do lists. The new item atop his list: reliable cellphone and wireless service throughout Dodger Stadium by the start of next season.

bill.shaikin@latimes.com

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