Review: Sonic's Peppermint Brownie Bark Shake Is Ho-Ho-Hum, While The Pretzel Bacon Double Sonic Smasher Is A True Treat

Sonic Drive-In is the modern world's version of the classic 1950s-style drive-in, where people would congregate to enjoy unabashedly tasty fast food from the comfort of their roomy automobiles. The mega-chain has kept up not just the tradition of ordering, receiving from a carhop, and eating in one's car and making an event of it, but also the kind of food sold at those joints so many decades ago. Sonic specializes in big, juicy burgers with lots and lots of toppings and creative condiments, and to wash those down, dozens of sweet and ice cold drinks, particularly shakes.

In October 2025, Sonic added one new burger and one new shake to its expansive and ever-evolving menu. The new entree sandwich builds on its successful line of smash burgers, with new flavors and textures joining up to create the Pretzel Bacon Double Sonic Smasher. On the shake front, Sonic is introducing the festive Peppermint Brownie Bark Shake.

Are the Pretzel Bacon Double Sonic Smasher and Peppermint Brownie Bark Shake worthy additions to the Sonic canon? Here's everything you need to make a decision, including a couple of taste tests.

Sonic understands fast food, and it knows it's got to bring in special, seasonal-specific items every now and then. The drive-in chain is getting ahead of the 2025 winter season with a brand new addition to its extensive lineup of shakes and frozen treats. Featuring ingredients and flavors that are strongly reminiscent of the upcoming December holiday season, the new-for-October 2025 Peppermint Brownie Bark Shake combines candy canes and baked goods.

The Peppermint Brownie Bark Shake starts with Sonic's shake base of creamy, vanilla-flavored soft serve and mixes in mint and chocolate. The former comes in the form of chopped chunks of rich and fudgy brownie pieces, and the latter via peppermints — the very kind of hard candy that Sonic throws in the bag for free on food orders — crushed into a fine near-powder. Those are blended into the frozen dessert to make a drinkable, mint chocolaty, holiday-ready treat, which is then topped with the usual Sonic adornments of whipped cream and a Maraschino cherry, as well as even more peppermint pieces.

Sonic Drive-In's latest burger isn't quite so Christmas-adjacent, but it's still generous and decadent. It's the latest entry to the restaurant's relatively new line of smash burgers (if you're a fan of this style, it's also worth seeking out Oklahoma onion burgers — a regional hamburger from the U.S. that everyone should try.) The Pretzel Bacon Double Sonic Smasher is a very big burger stacked with carefully chosen ingredients both inside and out. The main attraction is a pair of thin, individually pressed patties of high quality Angus beef grilled until the edges are blackened and crispy. That's the foundation for plenty of American-style cheese, slices of bacon, creamy mustard, and crispy, crunchy, fried onions.

That's a smash burger with bacon, but Sonic takes it up another notch by eschewing its regular buns in favor of a new idea. The bun is made in the style of a pretzel, with all of its implied sweetness, doughiness, chewiness, and saltiness.

On October 20, 2025, both the Peppermint Brownie Bark Shake and the Pretzel Bacon Double Sonic Smasher went on sale via the Sonic app, and from November 3 they will be available nationwide at the more than 3,400 Sonic Drive-In restaurants located throughout the United States. Sonic doesn't have separate breakfast and lunch hours, so both the new soft serve-based shake and the newest version of the Sonic Smasher will be available all day, every day, at the fast food chain's many outlets.

While the Peppermint Brownie Bark Shake and the Pretzel Bacon Double Sonic Smasher are limited-time only products for the foreseeable future, they'll be available to order at Sonic in the same way as everything from the permanent, full-time menu. Customers can go through the Sonic drive-through, or park in one of their local restaurant's many menu-outfitted ports and order via speaker for carside service. Sonic also operates a full-serve website and smartphone app, which allows for advance or immediate ordering.

Sonic's newest version of its Double Sonic Smasher is the Pretzel Bacon Double Sonic Smasher. The restaurant manages to pack a lot of food into a moderately large package, and accordingly it offers about a meal's worth of nutrition, and then some in a few categories. Made in the standard way with cheese, bacon, mustard, fried onions, beef, and a pretzel bun, the Pretzel Bacon Double Sonic Smasher has 590 calories, 33 grams of protein, 11 grams of carbohydrate, and 47 grams of fat, of which 16 is the more unhealthy saturated fat, according to Sonic. It also includes 115 milligrams of cholesterol and 1510 milligrams of sodium.

The newest milkshake on the Sonic menu, the seasonal Peppermint Brownie Bark Shake, has a lot of carbohydrates, particularly sugar, because it's made up of so many other sweets. Consisting of vanilla soft serve, crushed peppermints, chocolate brownie chunks, whipped topping, and a cherry, the shake comes in mini, small, medium, and large sizes. The medium version has 900 calories, 14 grams of protein, and 34 grams of fat, of which 25 is saturated fat. The shake adds 142 carbohydrates to one's daily consumption, and of that 115 grams is sugar.

It already felt like we were getting a little ahead of ourselves with a mid-October introduction of what's definitely supposed to be Sonic's contribution to the Christmas 2025 fast food season. While it looked like snow and was studded with tiny but still recognizable bits of candy cane, Sonic's Peppermint Brownie Bark Shake failed to ramp up anticipation for the so-called most wonderful time of the year. That's probably because nothing can get past the cloying sweetness of the Sonic shake base, a vanilla-flavored soft serve. The entire drinkable treat just tastes like a vanilla shake with other ingredients piled on top, because they certainly don't blend in.

Not much promised peppermint flavor could be found in Sonic's Peppermint Brownie Bark Shake. The crunch of the candy provided a novel and pleasing texture and an interruption in the smoothness, but there wasn't a lot of peppermint taste that came through. The chocolate offered an opposite situation. That flavor managed to push past the vanilla, but there wasn't enough to be evocative of bark. And while brownie bits were the add-in advertised, what was used tasted and felt far more like generic chocolate candy bits than anything baked. That would be more authentically bark-like, but it doesn't do the trick. Sonic's Peppermint Brownie Bark Shake, in the end, is a vanilla shake with a little bit of red and brown in it.

Everybody knows a burger, and most regular fast food customers enjoy burgers. But creating something new or innovative in the burger space, to get ahead of the competition while remaining recognizable and palatable to a large audience, is a tricky idea. All a place like Sonic can do is break down the idea of a burger to its individual components and significantly elevate or improve each thing. That's what Sonic did with its Pretzel Bacon Double Sonic Smasher.

Gone is the usual processed white bun most commonly used on fast food burgers, replaced with a large split round pretzel. Much like the soft pretzel sticks on Sonic's snack menu, this pretzel is very soft and chewy but thick and weighty enough to support a miniature mountain of materials. The slightly sour and also sweet bread pairs well with the greasy, fatty, salty patties made from top-notch Angus beef, pressed thin until grilled until a tasty, smoky char takes hold. 

So much American cheese is used that one can taste it (it often disappears in a fast food burger), especially as it mixes with the meat and joins up with the bacon. What makes this good burger a great burger are the toppers: Crispy fried onions rather than grilled ones give a crunchiness and savoriness. The mustard is tangy, sweet, and undercuts the fattiness found elsewhere. The Pretzel Bacon Double Sonic Smasher is very well constructed.

So Sonic Drive-In has two new items releasing in the mid-fall, positioned to last through the end of the year and into the holiday season, and only one of them is a welcome addition that could feasibly be a candidate for year-round menu status. The Peppermint Brownie Bark Shake is exactly the kind of thing people want to eat as the holidays and cold winter months approach. But while it had its merits — peppermint pieces inside ice cream is usually delicious, crunchy, and delightful — the finished product was lackluster and lacking anything that made it standout from Sonic's many other shakes.

As for the less seasonally specific Pretzel Bacon Double Sonic Smasher: That's just a well-crafted burger with many layers of hidden treasure. Well-cooked patties with crispy edges, plus a bun good enough to eat on its own, and condiments not normally found in Sonic or most other fast food burgers — crispy onions and a next-level mustard — sent this right to the top of Sonic's already substantial and competitive burger menu. Try the burger, skip the shake.