Tuesday, May 21, 2024

Peanut Butter Bars with Oatmeal

Sometimes I just gotta have a peanut butter dessert. These delicious peanut butter bars with oatmeal are one of my favorites.

A soft pb cookie bar with an extra layer of peanut butter and slathered with a thick layer of chocolate frosting. You know you want some!

It's is the most delicious treat for peanut butter lovers!

peanut butter bars

I recently made these for my son's football team. A couple of us were assigned to bring desserts. I brought two pans of these bars.

Let me tell you, they disappeared so quickly. There's just something about a homemade dessert that is WAY more appealing than store bought treats. They taste SO much better!

You're going to love these chewy peanut butter oatmeal bars too!

Peanut Butter Bars with Oatmeal

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peanut butter bars with oatmeal
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My mom always called these treats peanut butter brownies. I've also heard them referred to as peanut butter squares. Some call them lunch lady peanut butter bars. Whatever you call them, they are yummy!

Try a butterfinger bar version by adding crushed butterfinger candy on top. It's so good!

You can throw together a batch of these fairly quickly. I like to make them earlier in the day and then frost them once they've cooled.


You will need just a few simple ingredients for peanut butter oatmeal cookie bars. I always have these ingredients on hand.
  • peanut butter
  • butter
  • sugar
  • brown sugar
  • eggs
  • vanilla extract
  • baking soda
  • salt
  • all purpose flour
  • quick oats
  • chocolate frosting (not pictured)

Peanut Butter

I have always used regular creamy peanut butter. I have no experience using natural peanut butter or other substitutions.

In cases of allergies, you could try subbing almond butter, sunflower seed butter or cashew butter. These may alter the texture slightly and the flavor of the oat bars will be different. Obviously you can't get peanut butter flavor without peanut butter.

You could also try cookie butter for a completely different flavor.

They will satisfy your sweet tooth regardless of the type of butter you use.


I always use instant oats, or quick cook oats. You can substitute old fashioned oats (sometimes called rolled oats) instead. The end result will be sturdier, chewier oatmeal bars.

ingredients needed for peanut butter bars

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You will need a few basic cooking supplies:

how to make peanut butter bars


  Let's get started.

cream butter, peanut butter and brown sugar

Begin with the butter, peanut butter and sugars. Mix together in a large bowl until smooth and creamy.

It's best if the butter is soft and spreadable. Let the butter sit out on the counter for an hour or so before starting.

add eggs and vanilla to batter

Add the eggs and vanilla and stir until combined.

adding flour to the peanut butter mixture

Add flour, baking soda and salt. I like to add all those dry ingredients into my little sifter and sift it all into the batter. It helps to disperse the baking soda and salt evenly throughout the whole mixture.

The flour sifter I have was passed down to me. I haven't seen this type available for sale. To use it, I fill with flour and then shake it into the bowl.

The sifters you can get now, generally have some kind of crank or squeeze handle that helps pass the flour through without having to shake it.

add oats to peanut butter mixture
Stir in the oats. I use quick oats for this oatmeal bar recipe.

Look at that dough. This is definitely a recipe where I lick the spoon! It's so good!

peanut butter bars - before and after baking

Spread oatmeal mixture into the bottom of a greased 9 X 13 baking dish. Bake at 350 for 20 minutes.

The edges will just barely be starting to turn golden brown. It will not seem quite done, the middle will still jiggle. This is what you want.

Do NOT overbake!! If baked too long the peanut butter bars will be dry.

peanut butter bar toppings

Immediately place about 1/2 cup of peanut butter on the bars. For best results, add it in small dabs and then place it back in the oven for 2 minutes to melt the peanut butter. 

Spread the melted peanut butter into an even layer over the bars. Cool completely before frosting with chocolate frosting. 

chocolate frosting on peanut butter squares

I have used store-bought frosting when in a rush.  But I prefer to make my own chocolate frosting.  (← See recipe) 

the best peanut butter bars recipe

The chocolate and peanut butter combination is so yummy! 


Peanut butter bars can be stored at room temperature in an airtight container. I usually just add some plastic wrap to the top of the pan they were baked in. 

They will stay good for 5-7 days. (If they're not eaten before then!)


Freeze the bars individually on a tray. Once the frosting is frozen they can be stored together in a freezer-safe container. They will stay good for 2-3 months in the freezer.



Don't forget to pin it!!
peanut butter bars school recipeoatmeal peanut butter bars


  1. I agree Rachel... homemade is always better and these bars look delicious!
    Thank you for sharing your recipes at Create, Bake, Grow and Gather this week.

  2. We featured your awesome post at Full Plate Thursday,454! Thanks so much for sharing your talent with us and hope you will come back soon!
    Miz Helen