These Peanut Butter Cookie bars are reminiscent of a retro dessert that used to be served at many cafeterias across the US! They’re incredibly soft, rich in peanut butter flavor, with bite from some added oats, and covered in a smooth and rich chocolate icing. My favorite thing about this recipe (besides how good they are) is how many they make. They bake up in a sheet pan, and because they’re rich, you can cut them fairly small, so it’s the perfect dessert to feed a crowd. I often take them to parties and potlucks because of this (as long as I’m sure it’s a function that’s safe for peanut recipes!)

Ingredients and Equipment List
- Peanut Butter – you can use creamy or chunky peanut butter. I’ve never tried this recipe with a natural peanut butter (if you do, let me know!) But standard brands like Skippy and Jiff work great.
- Butter – unless you have an allergy or food intolerance, I recommend real butter (salted).
- Sugars – you’ll use a combination of granulated white sugar and light brown sugar.
- Oats – quick oats give these bars extra chew. If you don’t have quick oats, I like to pulse my old fashioned oats in the blender a few times to break them up just a bit.
- Cocoa Powder – cocoa powder is used in the icing, and you’ll want to used unsweetened.

Instructions
These cookies are incredibly quick and easy to whip up. It’s simply a basic cookie dough, frosted with the icing while it’s still warm.






- Make Dough: This is standard cookie making procedure here. You’ll cream together butter and sugar, then add peanut butter, eggs, and vanilla.
- Whisk together your dry ingredients and add those until combined.
- Stir in the oats.
- Press into a parchment-lined baking sheet and bake.
- Now, right here there’s an optional step: If you want to go full send, you can also drizzle on some melted peanut butter on top of the warm bars so there’s a layer of peanut butter underneath the chocolate icing. I used to always make them that way, and it’s deliciously indulgent, but I think they’re equally fantastic (and a little less rich) with out the PB layer so I usually skip that step these days.
- Mix up your frosting and spread on top of warm bars.
- Wait until they’re cool to slice!




Frequently Asked Questions
- Can these be made ahead of time? YES! They are are actually extra great made ahead of time (dare I say better on day 2?) Since they’re super soft they just seem to get better. You can cover the cooled pan in foil or plastic wrap and cut on day 2, or keep the sliced bars in an airtight container. I would also imagine they freeze well, though I haven’t tried that.



Chocolate-Frosted Peanut Butter Cookie Bars {School Lunch Peanut Butter Fingers}
Equipment
Ingredients
For the Cookie Base
- 1 cup real butter 2 sticks at room temperature
- 1 cup granulated sugar
- 2 cups brown sugar
- 1 ½ cups peanut butter chunky or smooth
- 3 eggs
- 2 teaspoons vanilla
- 1 ½ teaspoons baking soda
- ½ teaspoons table salt
- 3 cups all purpose flour
- 3 cups quick oats
- ¾ – 1 cup peanut butter optional, see notes in recipe below
For the Fudge Frosting
- 4 cups powdered sugar
- ½ cup cocoa powder
- ¼ teaspoon table salt
- ⅓ cup butter softened; make sure it’s really soft, you can microwave it if you need to – even melted is ok!
- ⅓ cup boiling water
- 1 teaspoon vanilla extract
Instructions
- Preheat oven to 350 degrees. Spray a rimmed cookie sheet (standard half-sheet pan) lightly with non-stick spray, or line with parchment paper, and set aside.
- Cream butter and sugars for 3-4 minutes, until creamy and slightly fluffy. Add peanut butter and vanilla and beat until combined. Add eggs, one at a time and beat between each addition. Combine flour, baking soda, and salt and add mixture to dough. Beat to combine. Add oats and mix until incorporated.
- Press dough into prepared pan into a flat layer. Bake for about 20-30 minutes, until puffed and set, but not browned on the edges. The center should be puffed and set, but still soft. The edges of the cookie bars should be puffed and kind of cracked like a baked cookie looks.
- Optional Step: Some people like to drizzle on a layer of melted peanut butter onto the warm bars so there's a layer of peanut butter under the icing. If you'd like to do that step, I just microwave 3/4-1 cup of peanut butter until it's melted and smooth and can easily be drizzled over the top of the warm bars. You'll want to spread it gently so you don't tear your cookie layer.
- When cookies are just about done, prepare frosting. Whisk together powdered sugar, cocoa powder and salt. Add butter, boiling water, and vanilla. Beat until smooth and glossy.
- When cookie crust is done baking, pour warm frosting over the top and spread into an even layer. Let bars cool before cutting in.








Questions & Reviews
Yum! I have everything for it right now to make it. I consider it healthy since it has oats in it and peanuts are protein!
You think like me Denise 😉
When did you guys start OBB Our Best Picks? So fun!!! I just bought a couple of those pans from Gygi’s about two weeks ago!
And, no, there are not enough recipes here for chocolate or peanut butter, and definitely not enough cookies.
You know, it’s always been sort of hiding there! We’re trying to get it all finished up (as in, filled up with all of our fave things) and then we’ll point out that it’s actually there! lol
I don’t think I can stop myself from clicking over there and getting that purdy turquoise immersion blender today 🙂
I am a strong believer that you can never have too much peanut butter + chocolate, or cookies! And to have them all in one is just divine.
My grandma used to make these…except instead of the frosting, she just threw some semisweet chocolate chips on top right when it came out of the oven. Once they melt, spread and eat! Probably not as tasty as the frosting recipe here…BUT, it works great to make this super quick/simple recipe even more so (plus less dishes)!
Great tip!
Oh wonderful 🙂 We have a ward pot luck this Sunday. These would be a perfect dessert!!
These are A-MAZING! My recipe for these came from a Ward Cookbook, which gives credit to Stephanie Wilkey. But they taste just like the peanut butter bars that they used to serve us for school lunch. Whoever or wherever they came from they are super delicious!
You’re right–these do look amazing. And dangerous. In my opinion, that’s the best combination. 🙂 Thanks for sharing!
Mmmm!! I have hot fudge stuff in my pantry! This will be a must have treat for today! Anything to use Ice cream for in an excessive heat warning!! Thank you for sharing this.
I remember these being served with our school lunches when I was a kid. I got my recipe from my Grandma, and it is very similar to yours. These are always a big hit & one of my most requested recipes!!!
This exact recipe has been in my family for years.. It came from the school lunch lady in springville Utah along long time ago! We love it!