Customers might not notice much of a difference, however, since the ingredient changes, expected by 2027, will impact less than 3% of Reese's products and less than 1% of the Hershey's portfolio.

The company told The Post its original Hershey's chocolate bar and Reese's Peanut Butter Cups already use real chocolate and will not be impacted. Rather, certain products like Reese's Fast Break candy bars and Reese's mini cups and special shapes will see changes.

Hershey said the decision to swap out the ingredients was made as its new leadership team came together, with CEO Kirk Tanner taking the helm last summer – and well before Brad Reese, whose grandfather HB Reese invented the famous treat, took aim at the candy giant.

"Right when I started with the company, we did a deep dive across our portfolio," Tanner told Bloomberg in an interview. "We're going to make some small investments to really align the portfolio to what the brand stands for."

The brand has faced blowback since Brad Reese launched a viral campaign lambasting the company for switching real chocolate with cheap compound coating made from vegetable oil in certain products, and sneakily replacing real peanut butter with peanut-butter flavored cremes.

"I can't just let it go. They're lowering the quality of ingredients, charging the same price and probably giving you a smaller product size," Reese, a retiree living in West Palm Beach, told The Post in February. "I'm really embarrassed as a member of the Reese family."

Reese – whose public comments against Hershey also sparked a fierce family feud, as The Post exclusively reported – said Wednesday that the company's announcement is not enough.

"They're untrustworthy. I don't believe them for a minute," he told The Post in an interview. "They're going to try to milk this compound they're using as long as they can."

"Saying it only affects 3% of their portfolio, that's total bunk. They're trying to minimize and they're trying to change the narrative."

Hershey told The Post it has ramped up research-and-development investments by 25%, saying it is "committed to making products consumers love and that means continually reviewing our recipes to meet evolving tastes and preferences."