SORRENTO VALLEY, CALIF. — The maker of Perfect Bar is putting a fresh spin on a classic confection. Perfect Snacks, a subsidiary of Mondelez International, Inc., is introducing refrigerated peanut butter cups in three varieties: milk chocolate, dark chocolate with sea salt, and dark chocolate coconut. 

The launch marks the brand’s expansion into a new category.

“We’re getting into confectionery and that indulgent eating occasion,” said Jessica Windell, marketing communications manager for Perfect Snacks. “This is the first true peanut butter cup that will sit in the fridge with peanut butter on the inside, chocolate on the outside.”

The products contain 7 to 8 grams of protein. Similar to the brand’s refrigerated bars and bites, the peanut butter cups feature a blend of dried whole food powders from fruits, vegetables and seeds. They are gluten-free, low-glycemic, Non-GMO Project verified and U.S.D.A. organic certified.

Perfect Snacks’ peanut butter cups will be merchandised next to its protein bars in the refrigerated snacking section of grocery stores.

The company began developing the product nearly a year ago, Ms. Windell said. Mondelez International, Deerfield, Ill., acquired a majority interest in Perfect Snacks in July. Mondelez, which makes Cadbury and Milka chocolate brands, has supplied insights on the confectionery category, Ms. Windell said.

“There’s definitely a lot to learn from them, but they’re also so keen on learning from us,” she said. “They’re like, ‘How do you guys take a product from conceptualization to distribution in six months?’ We’re like, ‘We just do.’”

Under the terms of the transaction, Mondelez said it plans to operate Perfect Snacks as a separate business while supporting distribution and product development.

“They’re looking to us to tell them how they can freshen up these older brands and get them in the fridge because that’s where the consumer is going,” Ms. Windell said. “The perimeter is growing 2.5x the center store.”

Perfect Snacks created a new market segment with the commercialization of a refrigerated protein bar nearly 15 years ago. In recent years, additional brands have followed, helping create a destination in the grocery store for fresh snacking, Ms. Windell said.

“The first five years, the sales team was bargaining with all these different buyers, like, ‘No, we belong here next to the eggs and milk.’ ‘No, we belong next to the yogurt.’ ‘No, we belong next to the fresh juices,’” she said. “Figuring out where we actually should live because there’s not any other products like ours was really hard for the first almost 10 years. It wasn’t really until five years ago that we started gaining traction in the fresh snacking set, and other brands started coming to the fridge.”

Perfect Bar varieties include dark chocolate almond, chocolate walnut brownie, mocha chip, blueberry cashew and coconut peanut butter, among others. The company also offers Perfect Bites, which are refrigerated bite-size portions packaged in resealable cups.

Consumers define fresh as “clean label, free of additives/preservatives and typically either refrigerated products or those found in the produce section,” according to David Lockwood, founder of Mintel Consulting. Pulling from the recent Mintel study “The Future of ‘Fresh,’” he identified refrigerated snack bars as part of the six packaged product segments that most clearly define the fresh snacking category. Fresh bars, and the perimeter of the store in general, have the attention of millennials and Generation Z, two consumer groups that demand healthful options.

“Consumer adoption of this ‘fresher is better’ mindset didn’t happen overnight,” Ms. Windell said.