A flavor tier list and review of all of the ONE protein bars I could get my hands on!
History-wise, ONE is constantly releasing new flavors. Some notable examples of this are their collab with Hershey’s. The Hershey’s Double Chocolate flavor was released in June 2025, and Hershey’s Cookies ‘n’ Creme and Reese’s Peanut Butter Lovers flavors were released in June 2024.
Overall Review & Verdict
There are definitely many uniquely advertised flavors here; however, what do they have in common?
Texturally, these are tougher, harder, and thinner than many protein bars I’ve had; they feel like they were compressed. At the same time, mostly uniform: a thin shell with a few swirls and a dense and thickly chewy protein-like filling layer. Some flavors have minor variations, but what ONE bars appear to be going for is something more standard and not over-the-top crazy like other brands do.
Similarly, the sweetness between most of the bars is milder than that of most other protein bars. With that, the flavors aren’t always as pronounced as they should be. On the other hand, I didn’t get any artificial or weird protein aftertastes from any of these. In a way, these are beginner-friendly, offering light flavors without any of the crazy mix-ins and toppings that other popular brands often contain.
As a side note, eat these at room temperature. I love cold candy and treats more than the next person, but these bars become hard and much more unpleasant to eat if you throw them in the fridge or they get too cold.
Flavor Ranking
1. Hershey’s Cookies ‘n’ Creme
Nearly identical to its Hershey’s bar candy counterpart–at least in terms of flavor–but less sweet. Of course, it also doesn’t have that traditional candy bar texture; instead, it’s reasonably thick, chewy, and has a soft-solid center and shell with bits of crunchy dark chocolate pieces. No artificialness either–well–it’s as artificial as its counterpart, more or less.
If you added a bit more sugar, you may have convinced me that this is some new, chewier, and thicker candy bar version of Hershey’s. In that sense, this is better than the candy bar version! Overall, for a protein bar, it’s just sweet enough and does its job, and does well at copying its candy bar counterpart well!
You can find my previous review of these here.
2. Hershey’s Double Chocolate
Is it the famous Hershey’s chocolate bar? Not really; it’s not that sweet, nor does it have a similar chocolate profile. What it is is an off-brand (not in a bad way), semi-dark, and mildly sweet chocolate, with notably no bitterness or artificialness. In a way, it tastes like a premium, more chunky chocolate bar as it has a pretty dense, lightly chewy filling, alongside embedded dark chocolate crunchy pieces, which aid in a more nuanced texture and bite.
Overall, this is simply a decent chocolate protein bar that you might mistake as a more fancy regular chocolate candy one. It’s reasonably sweet with a satisfying enough mouthfeel, with the real standout being no fake protein taste! Although it is disappointing, it missed the mark on the traditional Hershey’s chocolate bar flavor!
3. Reese’s Peanut Butter Lovers
They’re pretty dense, thick, smooth, and enjoyably soft. Light crunches from the embedded peanut bits provide some nuance to the texture. Flavor-wise, the entire bar is an authentic Reese’s peanut butter inside, albeit just a tad toned down on the sweetness. Anyone ever have their Peanut Butter Lovers cups or cereal? Just like those! There is nothing really artificial or any protein weirdness going on here! Overall, it’s pretty good if you’re craving something peanutty, although I’d like some contrasting chocolate and some extra sugar!
Note: This is also featured in my Reese’s treats review.
4. Maple Glazed
Surprisingly softer and less chewy than most here, as if it was either made a little differently or I got a dud (a good dud, that is!).
They smell strongly like a sweet maple candle… ew? But it does smell good! On top of that, it’s definitely sweeter than most on the list, but still has somewhere between a mild and moderate sugar level. Smells and sugar aside, the actual flavor is very tasty and definitely not like a waxy candle; however, there is just a hint of artificialness that doesn’t detract from the experience. As advertised, it’s maple, a creamy and candy-ish one at that, and notably, it sticks out more than most others on this list, likely due to its added sugar.
In terms of looks, it has a white shell with the typical protein center. Nothing crazy on this front.
5. S’mores
A cocoa chocolate tasting shell, and unlike most on this list, has embedded bits in the center–white chocolate pieces that seem to provide additions to the flavor and mouthfeel. Speaking of flavor, I get them all: cocoa, marshmallow, and a clear buttery graham. Each one is equally represented, none overpowering the other. Unfortunately, this bar isn’t sweet enough to bring it fully out. Honestly, if they were just sweeter–the flavor profile of this is perfect, it would absolutely taste like you’re eating a s’more in protein bar form.
6. Blueberry Cobbler
First off, I immediately thought these were pretty! A white shell with pretty pastel swirls–neat! On top of this, the inside filling also has specs of what appears to be blueberry, which provides an occasional minuscule crunch when you bite into it.
Taste-wise, it’s definitely a creamy, authetic blueberry, not a cobbler, as it lacks the doughy and buttery tastes. The specs of blueberry are also nice, as it feels like genuine, slightly crunchy blueberry pieces! If you want something that isn’t too sweet and want an enjoyable blueberry bar, this is for you.
7. Peanut Butter Cup
Opening this up, I get a whiff of both peanut butter and chocolate. It has a semi-dark chocolate shell with swirls of peanut butter on top, and, more importantly, has a noticeable layer of thin, lightly crunchy peanuts–definitely the most crunchy bar on this list. Don’t mistake the crunchy part, though; it’s not over the top by any means, as the layer is on the thinner side.
The inside gives you an explicit peanut while the shell provides a background of semi-dark chocolate and hints of peanut. Together, it’s a good combination and reminds me of your typical chocolate peanut butter treat. Sweetness-wise, it’s reasonable, though it could be stronger to bring out the flavors more.
8. Fruity Cereal
A white shell with the protein filling, nothing else, it has a completely uniform mouthfeel.
The flavor is where it shines. It’s very similar to a Froot Loops, perhaps an off-brand. I don’t mean this in a bad way, either, you really get the authetic, generic fruity cereal taste. The sweetness in cereal terms is also close to Froot Loops, but unfortunately, it falls short of that and dulls this bar more than it should.
Nonetheless, while I talked poorly about this bar, the taste is authetic. If anything, I’d like some more sweetness and even some cereal bits to really bring this alive.
9. Chocolate Almond Bliss
Biting in, it’s an authentic, mild to moderately sweet, nutty almond and light chocolate. I’m genuinely impressed by how both of the flavors work so well with one another. Weirdly, it reminds me of Almond Joy without the coconut flavor–and absolutely not nearly as sweet–the sugar content is about right, not too strong or too light. Between the chocolate and almond, the almond itself is more prominent, so if you’re not into more nutty-based bars, you may want to avoid this.
Nonetheless, what also stood out were the few large sliced almond bits embedded right below the chocolate shell. They give you a notable and appreciable light crunch every few bites.
10. Birthday Cake
A noticeably thin white chocolate shell with tiny colored pieces on top. Honestly, the shell here was so thin that you could see the inside filling. The inside has the usual dense protein filling. What you get from this is a complete uniform, uninteresting texture.
What especially doesn’t help is the fact that, despite this being a birthday cake flavor, it’s just not sweet enough. This is a birthday cake after all! And while it is mildly sweet, the flavor is an authentic birthday vanilla taste, so I will give it credit there. It’s just disappointing that as someone who loves birthday cake flavor protein bars, it falls so short due to its ultra tame sweetness and flavor, as well as boring mouthfeel from the equally boring texture–like, at least include sprinkles that are actually crunchy!
11. Cinnamon Roll
This has a white shell with light brown swirls and the ONE protein bar filling. It’s uniform in texture.
The flavor is an equal sugary cinnamon and a light amount of creaminess. I wouldn’t say it’s explicitly a cinnamon roll as it’s missing the icing and doughy/buttery flavors. And of course, like many of the other bars, it’s not very sweet. Essentially, a light-tasting cinnamon-sugar protein bar–kind of boring and not as good as it could have been, in my opinion.
12. Lemon Cake
Lemon? Eh. It’s a sugary lemon, but don’t get me wrong, it’s not that sweet. It’s also not punchy or that pronounced by any means, perhaps toned down by not only the lack of sugar but also its creamy white shell. The texture appears uniform throughout, too.
This bar feels like it was made for someone who isn’t a fan of lemon in the first place. Secondly, where is the cake part? I don’t get any dough or cake-like flavor in this whatsoever!
13. Chocolate Chip Cookie Dough
Why is this so tough? When you bite in, you nearly have to pry it apart! It feels like an overly hard and chewy cookie dough. At the same time, at least, there is a generous amount of chocolate bits on the inside that provide a satisfying crunch.
The shell is milk chocolate, and the center provides a mildly sweet cookie-dough-ish flavor. Unfortunately, it’s a lot less sweet than most others on this list, so the cookie dough isn’t as explicit as it should be. It’s there, or maybe not really–this bar needs help in the sweetness department!
But, anyway, I really can’t get over that stubborn mouthfeel when you bite in. It’s just too tough–this isn’t supposed to be beef jerky!