During my first winter of college, I found myself enrolled in a Monday night chemistry lab from 7-10 pm… Followed by a three-hour block of back-to-back lectures that started at 7:30 am the following morning. Many weeks, it felt as if I had just barely closed my eyes by the time my alarm rang, jolting me awake in the pitch black darkness of my dorm room.
At least two others on my floor ended up with the same tough scheduling luck, so the three of us walked down to the parking lot in hoodies and sweats on those Tuesday mornings and rode our bikes through the thick, heavy fog to campus. After trampling into the massive hall and pulling out pencils, we scribbled down notes as the much too chipper professor explained new concepts and balanced acid-base reaction equations on an overhead projector.
As soon as she released us, I raced across the road to a smaller room for a liberal arts lesson. While that lecturer spoke, I constantly jotted down more notes on fresh sheets of paper, only briefly pausing to click up more lead in my mechanical pencil… Because doing that helped me stay awake and alert after a night of not nearly enough sleep.
Finally, just after 10:30 am, I hopped back on my bike and navigated through the throngs of students over to the gym. Because nearly four hours had passed since breakfast, I quickly scarfed down a granola bar before beginning my workout.
Living in the freshman dorms, I lacked a kitchen, so I opted for the convenience of store-bought snacks to fuel my gym sessions…
But these healthy peanut butter oatmeal bars would’ve been a fantastic homemade alternative — for both breakfasts and snacks on those rushed Tuesday mornings! They’re a delicious grab-and-go option, and they’re perfect for meal prepping too. (Or snack prepping, if you prefer that instead! 😉 )
QUICK OVERVIEW – HEALTHY PEANUT BUTTER OATMEAL BARS
Difficulty: Fairly easy, including for many beginner bakers.
Taste: Lightly sweetened, similar to breakfast scones or muffins, with a cozy oat flavor surrounded by notes of peanut butter.
Texture: Moist, soft, and chewy — very similar to regular oatmeal cookies!
KEY INGREDIENTS TO MAKE HEALTHY PEANUT BUTTER OATMEAL BARS
Let’s go over what you’ll need to make these healthy peanut butter oatmeal bars! You probably have many of these ingredients in your kitchen already. If not, many of them are easily customizable to what you do have on hand!
Oats. These are the star of the show! Although with a recipe title like “peanut butter oatmeal bars,” I’m guessing you’ve already figured that out…
To make these bars, you’ll need instant oats. They’re also called “quick cooking” and “one minute” oats. They’re not the ones sold in individual packets with flavors such as apple cinnamon or maple brown sugar! Instead, instant oats only contain one ingredient (oats!), and they’re smaller and thinner than old-fashioned rolled oats.
That size difference is important! Because they’re smaller and thinner, instant oats soften faster — and that gives your healthy peanut butter oatmeal bars the best soft and chewy texture.
Tip: Certified gluten-free instant oats work perfectly too, if you’d like to make these peanut butter oatmeal bars gluten-free!
Flour. To make these bars healthier, I opted for whole wheat flour. I love how its flavor accentuates the coziness of the oats, and whole wheat flour also gives these peanut butter oatmeal bars more fiber and micronutrients. I call that a win-win!
Tip: If you’d like to make your healthy peanut butter oatmeal bars gluten-free, then see the Notes section of the recipe. I’ve shared my top recommendations there!
Cinnamon. I know many peanut butter cookie and bar recipes don’t include this… But there’s just something so perfect about the pairing of oats and cinnamon. It’s almost like salt and pepper, cereal and milk, or frosting and cake. It just feels too weird making oatmeal cookies or bars without cinnamon!
So yes, I sprinkled in a small amount — just enough to give these peanut butter oatmeal bars a background warmth and coziness. I promise the peanut flavor still shines through!
Tip: I highly recommend Saigon cinnamon! It has a slightly stronger, sweeter, and richer flavor than regular cinnamon. I’m obsessed, and it’s practically the only kind I now use in my baking! Many stores have started stocking it, but I often buy it online here. (It’s really affordable!)
Egg white. This binds together the other ingredients. It also gives your peanut butter oatmeal bars a little protein boost!
Peanut butter. I used my homemade peanut butter. You only need 5 minutes to make it — super quick and easy! If you’d rather use store-bought, then make sure it’s (a) creamy peanut butter and (b) the natural kind that only contains peanuts and salt. It should be liquidy at room temperature, and give it a good, thorough stir to reincorporate any oil that might have collected on the surface before measuring it.
Tip: Do not substitute crunchy peanut butter! In these oatmeal bars, the peanut butter is actually considered a “liquid” ingredient because it contributes to the total liquid volume. The peanut bits in crunchy peanut butter reduce the amount of “liquid” available, which then throws off the ratio of wet and dry ingredients… And that can make your oatmeal bars crumbly or dry. So for the best soft and chewy texture — and the best peanut flavor! — use natural-style creamy peanut butter.
Sweetener. Pure maple syrup is the sweetener you’ll need today! It’s the kind that comes directly from maple trees, and it only contains one ingredient: maple syrup. It’s often sold in thin glass bottles or squat plastic jugs (like this!).
I don’t recommend substituting pancake syrup or sugar-free maple syrup. Those contain other ingredients, which often affects the texture of your oatmeal bars. This is especially true of the latter! Sugar-free maple syrup is generally water-based, so substituting it can yield bars that are more cakey, bready, or dry.
Milk. To make sure these peanut butter oatmeal bars qualify as breakfasts and snacks, rather than dessert, you’ll use half the amount of sweetener compared to traditional oatmeal cookie recipes. (Hence why they’re lightly sweetened!) To compensate for the “missing” other half, you’ll stir in milk. Just about any kind of milk will work!
I use unsweetened vanilla almond milk the most because that’s what many of my family members like and keep on hand, but I also love unsweetened cashew milk because it’s so thick and creamy. If you go with either of those options, your healthy peanut butter oatmeal bars will be dairy-free!
HOW TO MAKE HEALTHY PEANUT BUTTER OATMEAL BARS
Gathered your ingredients? Then let’s talk about how to make the best peanut butter oatmeal bars! Like I promised above, they’re simple and straightforward, but I still have some tips to share with you. The first one is…
Measure correctly. I know, I know… You might be tired of me repeating this over and over. But before you roll your eyes (or maybe even while you do!), I’m going to emphasize it again.
It’s really important to measure the ingredients correctly — particularly the oats and flour! — using this method or a kitchen scale. Too much of either one will make the batter too thick, and it’ll also yield bars that bready, crumbly, or dry. This is especially true for the oats. They act like little sponges and soak up lots of moisture from batters and doughs!
Use the correct pan size. Double check the dimensions along the top edge of your pan! Square pans are measured according to their tops, and you need an 8”-square pan to make these healthy peanut butter oatmeal bars. That means that the top edge should be 8” long.
Many square baking pans have sloped sides, so the top rim isn’t the same length as the bottom edge. If your square pan measures 9” across the top but only 8” across the bottom, it’s a 9”-square pan — and it’s too big for this recipe. (Your bars would turn out really thin and be prone to overbaking!) Reach for a square baking dish that’s 8” across the top instead!
Do not overbake. Besides adding too much flour or too many oats, this is the other #1 culprit that yields cakey, bready, or dry bars. These peanut butter oatmeal bars bake quickly, so don’t stray too far from the kitchen! They’re ready to come out of the oven when the edges feel firm but the center still appears glossy and a bit underdone. The heat from the pan will continue to cook that center all the way through while you let the bars cool and set. (More on that momentarily!)
If you left them in the oven until the center felt firm as well, your bars would turn out cakey and dry — not beautifully soft, chewy, and moist like they’re supposed to be! Just like when baking homemade brownies, pull them out a little sooner than you might think for the best possible texture.
Cool + set. Yup, you need a bit of patience for this step… I’m insisting that you let your healthy peanut butter oatmeal cookie bars cool completely to room temperature and set for 4+ hours for the best soft and chewy texture. They taste more cake-like if you cut into them sooner, but if you’re able to wait long enough, they have an incredible consistency that’s almost exactly like regular oatmeal cookies.
Tip: If you can’t wait quite that long, then put your pan in the refrigerator for 2+ hours once the bars are at room temperature to speed up the process!
FAQS ABOUT HEALTHY PEANUT BUTTER OATMEAL BARS
Are these peanut butter oatmeal bars gluten-free, clean eating, low fat, low calorie, or low sugar?
Yes — to everything! These healthy peanut butter oatmeal bars are naturally clean eating, low fat, and low calorie (compared to many more traditional recipes!). They’re dairy-free with no white sugar, and I included my top gluten-free recommendations in the Notes section of the recipe too.
Can I use old-fashioned rolled oats?
Kind of! Measure out the same amount of old-fashioned rolled oats, but pulse them in a blender or food processor until they’re about ⅛ to ¼ of their original size before using them. This makes them closer in size to instant oats, so you’ll basically achieve the same soft and chewy texture.
What about a different flour?
You sure can! White whole wheat flour, whole wheat pastry flour, and all-purpose flour all work just as well. Oat flour (gluten-free, if necessary!) is another good alternative, but be very careful when measuring it because it tends to be more absorbent than wheat-based flours.
Could I use the whole egg, not just the white?
Absolutely! Just reduce the milk by ½ tablespoon to compensate for the added liquid volume from the yolk.
Is it okay to substitute crunchy peanut butter?
No — and I beg that you don’t! It yields bars that are cakey, bready, or dry. (See the “peanut butter” header in the “Key Ingredients to Make Healthy Peanut Butter Oatmeal Bars” section above for more information.)
What about another type of milk?
Yes again! Just about any type will work, so feel free to use whatever you already have in your fridge. No need for a special trip to the grocery store!
My bars turned out cakey, bready, or dry. Why is that?
There are a few potential culprits! The two most common ones are too many oats or too much flour. Make sure you’re measuring these correctly — and do not scoop either one from its container! (See the “measure correctly” header in the “How to Make Healthy Peanut Butter Oatmeal Bars” section above for more info.)
Two other reasons would be using the wrong pan size or baking them for too long. Double check that you’re using an 8”-square pan (not a 9” one!), and pull it out of the oven when the center is still a bit glossy and underdone. (See the “use the correct pan size” and “do not overbake” headers in the “How to Make Healthy Peanut Butter Oatmeal Bars” section above for more info.)
Finally, give your oatmeal bars enough time to fully cool and set before slicing them into squares. They turn softer and chewier the longer they’re allowed to rest! (See the “cool + set” header in the “How to Make Healthy Peanut Butter Oatmeal Bars” section above for more info.)
How should I store these healthy peanut butter oatmeal bars? And how long do they last?
I store these bars in an airtight container in the refrigerator. They should keep for at least four days, often longer — if they even last that long! They also freeze and thaw really well, if you’d like to keep a stash in your freezer!
My college self would be leaping out of bed for one of these right about now! 😉 And when you make your own, remember to snap a picture and share it on Instagram using #amyshealthybaking and tagging @amyshealthybaking IN the photo itself! (That guarantees I’ll see your picture! 🙂 ) I’d love to see your healthy peanut butter oatmeal bars!
Healthy Peanut Butter Oatmeal Bars
- 1 cup (100g) instant oats (gluten-free if necessary and measured like this)
- ¾ cup (90g) whole wheat flour or gluten-free* flour (measured like this)
- 1 ½ tsp baking powder
- ¾ tsp ground cinnamon
- ⅛ tsp salt
- 1 large egg white (room temperature)
- 1 tsp vanilla extract
- ¼ cup (64g) homemade creamy peanut butter (room temperature)
- ½ cup (120mL) pure maple syrup (room temperature)
- 5 tbsp (75mL) unsweetened vanilla almond milk (room temperature)
- Preheat the oven to 300°F, and coat an 8”-square pan with nonstick cooking spray.
- In a medium bowl, whisk together the oats, flour, baking powder, cinnamon, and salt. In a separate bowl, whisk together the egg white and vanilla. Stir in the peanut butter until completely incorporated. Stir in the maple syrup until thoroughly incorporated. Stir in the milk. Add in the oat mixture, and stir until just incorporated.
- Spread the mixture into the prepared pan. Bake at 300°F for 10-12 minutes. Cool completely to room temperature in the pan. Allow them to rest for an additional 4+ hours once at room temperature for the best soft and chewy texture before slicing into squares.
View Nutrition Information + Weight Watchers Points
You may also like Amy’s other recipes…
♡ Healthy Peanut Butter Granola Bars
♡ Healthy Peanut Butter Protein Bars
♡ Healthy Brownie & Oat Snack Bars
♡ Healthy Oatmeal Raisin Snack Cake
♡ Healthy Blueberry Oatmeal Snack Cake
♡ Healthy Peanut Butter Oatmeal Breakfast Cookies
♡ …and the rest of Amy’s healthy peanut butter flavored recipes and healthy snack recipes!