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Indulge in the ultimate combination of peanut butter with these chocolate peanut butter oatmeal bars. These bars feature a chewy, peanut buttery oatmeal base topped with a generous layer of rich, creamy chocolate frosting. They’re and easy dessert, using simple ingredients and perfect for any occasion, from casual get-togethers to special celebrations. You don’t really need a reason to bake desserts. The hardest part of this recipe is not eating the whole pan in one day. Each bite offers a delightful balance of sweetness and texture that will leave you wanting more.
This recipe is the perfect choice for creamy peanut butter lovers. If you are a self-proclaimed nutty flavor lover, try my other peanut butter desserts like Peanut Butter Swirl Frozen Custard Ice Cream Recipe and my The Best Bakery Style Peanut Butter Cookies. After you do, be sure to comment below and let me know which is your favorite dessert.

The Chemistry of Chocolate Peanut Butter Oatmeal Bars
The magic behind this delicious treat lies in the chemistry of baking. The oats provide a chewy texture, while the peanut butter adds moisture and richness, preventing the bars from becoming dry. The baking soda acts as a leavening agent, helping the bars rise slightly and achieve a tender crumb. The chocolate frosting, made with a combination of powdered sugar and cocoa powder, is stabilized with butter and heavy cream to create a smooth, spreadable texture that sets perfectly on top of the cooled bars. Making an irresistible chocolate layer.
What is in peanut butter oatmeal bars?
Granulated Sugar
Adds sweetness, provides a caramelized flavor and crisp texture. Sugar assists with rising when creamed with butter. It helps add moisture to your treat and helps it evenly spread as it melts into a liquid in the heat of the oven. Sugar also helps with naturally preserving your baked treat.
Brown Sugar
Is granulated sugar with a little molasses mixed in. Molasses is a somewhat smoky flavored natural sweetener, which makes brown sugar a bit sweeter than granulated sugar. Brown sugar draws more moisture into your treat, keeping it softer for longer. It’s also more acidic, which means it will help activate your baking soda.
Unsalted Butter
It is always important to use unsalted butter when baking. If you use salted butter, you have no way of knowing how much salt you are adding to your dough or batter and it will result in an overly salted treat.
Butter adds fats to your dough or batter which helps with moistness, flavor and texture. Butter melts at body temperature, which creates a ‘melt in your mouth’ sensation.
When baking with butter, the temperature is important. If the butter is too warm, your treat will melt too fast and overspread in the oven, leaving you with a greasy, flat mess. If your butter is too cold, it will have the opposite problem and not melt down enough, leaving your treat too thick.
Eggs
Adds both a protein (egg whites) and fat (egg yolks). The egg whites help with rising because, when foamed, little air pockets get trapped inside the egg white mixture. The water content in egg whites encourages steam while baking, which helps with gluten formation, resulting in nice and thick treats. Egg yolks have emulsifying properties that bring batters and doughs together and help them from collapsing. Unless otherwise specified, always use large eggs.
Vanilla Extract
When using pure vanilla extract, as opposed to imitation flavoring, it will add the deep rich flavor that everybody wants in a treat.
Peanut Butter
Adds another fat into your dough or batter that melts easily, allowing your treat to spread a little more. It will also add a creamy texture & rich flavor to your treat.
Baking Soda
Elevates the pH level of your batter or dough. It increases the spread in your treat and encourages browning, which gives the crispy outside and soft inside texture that everyone loves. Baking soda needs both an acid and a liquid to react. Things that will activate your baking soda are: vinegar, fruit juice, molasses, brown sugar, tartar, buttermilk and sour cream. Baking soda only reacts once, which is right when it’s mixed into your batter or dough. The soda creates little air bubbles all throughout your treat. When the air bubbles get heated up in the oven, they expand.
Fine Sea Salt
Enhances flavor, adds balance, masks any bitter flavors. Salt is the most powerful and oldest preservative. Always make sure to use fine sea salt so it melts down at the right speed in the heat of the oven. If you use larger granule salt, it will not melt down fully when baked and will leave salt crystals throughout your treat, making it crunch like you dropped it into sand. All of my favorite salts are from Redmond and I have a discount code for you to get 15% off.
All-purpose Flour
Builds structure as it absorbs liquids and expands. All-purpose flour falls in the middle of bread flour (high in gluten) and cake flour (low in gluten). It’s exactly what it is named, all-purpose, the most universal flour that can be used in most baked goods.
Oats
Provides some fiber. Absorbs liquid in the dough or batter, making a chewy texture. It adds a slight nutty flavor and a layer of nutritional value, making baked treats slightly more wholesome.
Whipzi Chocolate Powdered Sugar
Creates a smooth and rich chocolate frosting.
Unsalted butter
Often the main ingredient of frosting, it adds structure to your buttercream. It also adds a smooth and velvety texture. Butter melts at body temperature, so it will make your frosting have a melt-in-your-mouth sensation.
Heavy Cream
Adds richness and a smooth consistency to the frosting.

How do you make chocolate peanut butter oatmeal bars?
Bars
- Preheat your oven to 350 degrees
- Add the white and brown sugar and the butter to a standing mixer bowl. If you do not want to use a standing mixer you can also use a large bowl and electric hand mixer.
- Mix on low until combined, then turn the speed up to high, and whip for 2 minutes until light and fluffy. For best results, you must properly cream your butter and sugar to incorporate air bubbles into the mixture.
- Stir peanut butter, eggs, and vanilla in at low speed until combined.
- Add the soda, salt, flour, and oats to the bowl. Turn the speed on low and mix until just combined.
- Press the peanut butter mixture into a greased and parchment paper-lined 9×13 pan. You can use your hands, the bottom of a cup, or a tiny rolling pin. Bake peanut butter bars for 25-30 minutes.
- Remove and allow the bars to cool inside the pan.
Frosting
- In a medium bowl, add the powdered sugar, butter, and cream. Mix on low until combined, then turn up the speed to high and whip for 2 minutes until light and fluffy.
- Spread the decadent chocolate topping all over the top of the bars.
- Cut the bars into small squares and enjoy; your taste buds will thank you for the perfect sweet treat!

Storage Tips
Store your chocolate peanut butter oatmeal bars in an airtight container to keep them fresh. They can be kept at room temperature for up to 4 days. For longer storage, refrigerate them for up to a week. Freezing them is an excellent option if you need to store them even longer.
These bars maintain their chewy texture and delicious flavor for several days when stored properly. They stay fresh for about four days at room temperature, while refrigeration extends their shelf life to about a week. For the best quality, consider freezing any bars you won’t consume within a week.
Freezing Options
This is the perfect dessert to freeze, place them in a single layer on a baking sheet and freeze until solid. Then, transfer them in an airtight container or freezer bag. This prevents them from sticking together and makes it easy to grab just one or two at a time. They can be frozen for up to 3 months. Thaw them at room temperature or in the refrigerator before serving.
Making Ahead
These peanut butter chocolate bars are a fantastic make-ahead dessert. You can prepare the bars and frosting separately a day or two in advance. Store the bars in an airtight container at room temperature and the frosting in the refrigerator. When ready to serve, spread the frosting over the bars and cut into squares.
Recommended Products
FAQs
Can I use natural peanut butter instead of creamy peanut butter?
Yes, you can use natural peanut butter, but remember that it might alter the texture slightly due to oil separation and because it is more chunky peanut butter. Stir it well before measuring to ensure an even distribution of oils and solids.
Can these bars be made gluten-free?
Absolutely! Substitute the all-purpose flour with a gluten-free blend suitable for baking, and ensure your oats are certified gluten-free. This will make the bars safe for those with gluten sensitivities.
How do I store these bars to keep them fresh?
Store the bars in an airtight container at room temperature for up to 4 days. For longer storage, keep them in the refrigerator for up to a week or freeze them for up to 3 months.
Can I use a different type of frosting?
Definitely! While the chocolate frosting perfectly complements the peanut butter oatmeal bars, you can experiment with other frostings, such as vanilla buttercream, cream cheese frosting, or even a peanut butter glaze.

Why make chocolate peanut butter oatmeal bars?
These chocolate peanut butter oatmeal bars are a must-try for any dessert lover, and may be one of the easiest desserts to bake with basic pantry ingredients. With their chewy texture and rich, chocolatey frosting, they’re sure to become a family favorite. Perfect for parties, potlucks, or just a sweet treat at home, these bars are as delightful to make as they are to eat.
I’ve always loved experimenting with classic flavor combinations, and these chocolate peanut butter oatmeal bars are a testament to that. Growing up, oatmeal cookies were a staple in our household, and I’ve always had a soft spot for anything involving peanut butter and chocolate. This recipe combines those childhood favorites into a single, mouthwatering treat that’s sure to become a favorite in your home too.
Recipes You May Love
- Big, Soft and Chewy Peanut Butter Chocolate Chip Cookies
- Browned Honey Oatmeal Cookies
- The Best Bakery Style Peanut Butter Cookies
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Chocolate Peanut Butter Oatmeal Bars Recipe
Ingredients
Bars
- 1/2 cup granulated sugar
- 1 cup brown sugar
- 1 cup unsalted butter
- 2 eggs
- 1 1/2 tsp vanilla extract
- 1 cup creamy peanut butter
- 1 tsp baking soda
- 1/2 tsp fine sea salt
- 1 1/2 cup all-purpose flour
- 2 cups oats
Frosting
- 3 cups Whipz Chocolate Powder Sugar **can substitute with 3 cups powdered sugar & 1/2 cup cocoa powder
- 1 cup unsalted butter
- 1/4 cup heavy whipping cream
Instructions
Bars
- Preheat your oven to 350 degrees
- Add the white and brown sugar and the butter to a standing mixer bowl.
- Mix on low until combined and then turn the speed up to high and whip for 2 minutes until light and fluffy.
- Stir in the peanut butter, eggs and vanilla on low speed until combined.
- Add the soda, salt, flour, and oats to the bowl. Turn the speed on low and mix until just combined.
- Press the dough into a greased and parchment paper-lined 9×13 pan. Bake for 25-30 minutes.
- Remove and allow the bars to cool inside the pan.
Frosting
- In a medium bowl, add the powdered sugar, butter, and cream. Mix on low until combined, then turn up the speed to high and whip for 2 minutes until light and fluffy.
- Spread the frosting all over the top of the bars & enjoy!
Nutrition
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