In many ways, M&M’s are the quintessential candy. Originally introduced in 1941, more than 400 million of the bite-sized, sugar-coated chocolates are produced in the US every day. And while chocolate, peanuts, and even pretzels have long filled those beloved candy spheres, in honor of its 75th anniversary the company has finally introduced the permanent addition of a new, gooey center: caramel.

Slated to hit stores in 2017, the new, chewy core was no small undertaking, calling for more than two years of development, and some 70 new employees as Mars Chocolate’s $270 million plant in Topeka, Kansas.

"It was a big technological challenge for us," Hank Izzo, vice president of research and development of Mars, told CNN Money. "We never before had a M&M lentil with a true soft center, so we had to figure out how to not make the chocolate too sticky or too soft that it could collapse.”

“Caramel is extremely trendy," Izzo added. "We want to be part of this category."

While other food companies like Nabisco have somewhat diluted their brands by offering a never-ending array of new products (Swedish fish-flavored Oreos, really?), there’s rarely a fresh spin on M&Ms, and people are of course freaking out about the innovation. The Facebook post announcing the news has racked roughly 9,000 likes, 3,000 shares, and 1,000 comments, and on Wednesday Twitter was flooded with excitement from fans.

[via CNN Money, Business Insider]