The fast-food chain keeps innovating and its latest addition should be very popular with some of its most-devoted fans.

The McFlurry seems like it’s been around forever, but as far as McDonald’s menu staples go, it’s relatively recent.

A mixture of soft-serve vanilla ice cream and various cookies and candies, the McFlurry is served with a signature spoon with a hole in the handle. Fast food aficionados have often said the dessert is McDonald’s  (MCD) – Get McDonald’s Corporation Report answer to Dairy Queen’s Blizzard, but the McFlurry has been around long enough at this point that it’s developed a fanbase of its own.

The treat was first introduced in 1995 by a franchise in New Brunswick, Canada. McDonald’s began slowly rolling it out at various locations before it was put on the menu at all locations in 1997.

McDonald’s typically gives its various franchises a fair amount of room to experiment with new ideas to see if they might work for a larger customer base, and different locations are often experimenting with new McFlurry ideas. 

 One eagle-eyed fast food fan has noticed that a few Southern California locations are trying out a new McFlurry iteration featuring an iconic American candy. 

A New McFlurry Has Been Discovered

A few locations in Southern California have been experimenting with a Hershey’s Mix McFlurry that features chunks of the chocolate bar mixed in. 

A staple American candy since the dawn of the 20th century, Hershey’s chocolate bars are the sort of thing that you would just assume are already standard go-tos for McFlurry mixes. But that’s surprisingly not the case.

As noted by the rather-well curated McDonald’s fandom wiki for McFlurry’s, the staple toppings include Snickers, Oreos, mini M&M’s, and Butterfingers. Various other flavors and ingredients get rotated on and off the menu all the time.

Why wasn’t Hershey’s already on the menu? Well, the answer is that it’s been on the menu before, and it’s been marketed as a “McFlurry Seduction” (which sounds NSFW) but it never sticks around. 

It’s hard to say why this is the case, but McDonald’s, like many other fast food companies, likes to rotate items like the McRib or the Shamrock Shake on a seasonal basis, in order to generate scarcity demand. (And these days, social media buzz.) Some fans might find this annoying, but this approach does seem to work as intended.

McFlurry Has Been a McProblem

The biggest challenge when it comes to adding a new McFlurry is that the machine which makes the ice cream treat breaks down a lot. That has led to a lot of customer anger and even a website fully dedicated to tracking whether the ice cream machine in any given store is actually operating.

Despite that, the McFlurry has built up a strong following even though you’re never quite sure if you’ll be able to get one. That’s partially because fast-food burger chains generally have very limited dessert options. Wendy’s (WEN) – Get Wendy’s Company (The) Report has its two Frosty flavors (chocolate and strawberry right now) while Restaurant Brands International’s (QSR) – Get Restaurant Brands International Inc. Report has ice cream and a few other items, but has never really made a mark in the dessert space.