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Retro-style Lunchroom Chocolate Peanut Butter Bars…taking it back to grade school today with these DELICIOUS peanut bars. Picture a doughy buttery, peanut butter cookie base, layered with creamy peanut butter, and the most delectable, roll your eyes back good chocolate frosting that’s rich and fudgy. The added bonus is that these bars require only pantry staple ingredients and take almost no effort to make. They’re sweet, salty, heavy on the peanut butter, extra chocolatey, and every last bite is truly delicious. The perfect treat to enjoy as an afternoon/after-school/homeschool snack and for any upcoming fall gatherings with family or friends.

Lunchroom Chocolate Peanut Butter Bars |

The truth really is that I love each and every recipe I share with you guys. I work endlessly to only share the best of the best with you guys. There are many, many…and I do mean many…recipes that you never see because they just aren’t good enough. The recipes I share with you guys have to be really good, so because of this, I love them all.

That said, I of course have some recipes I might favor slightly more than others.

Case in point, these peanut bars. It’s no secret that my favorite desserts include chocolate and peanut butter. That’s fairly obvious from the amount of peanut butter and chocolate recipes that can be found on the site. I could not love these chocolate frosted peanut bars more. If you could see me typing away, you’d see my excitement

It’s dorky, I know, but I love it when I really LOVE a recipe. That said, I have so many reasons why I love this recipe…and it’s not just about the taste.

Peanut Butter Bars before adding chocolate

So here comes the story.

I’ve been talking about this all week, but it’s back to school time, and for me, that brings back a lot of feelings. For as much as I hated school growing up, I always somewhat enjoyed this time. Back to school meant, new clothes, new supplies, and the excitement of the fall season ahead.

And also? Lunchroom desserts. YES, you guys know what I’m talking about.

Peanut Butter Bars before adding chocolate

For me personally, I never bought a school lunch. Mom always packed our lunches when we were younger. But the one thing we did always get to enjoy was pizza day. Oh, pizza day. If I’m remembering correctly, it only happened once a month (if not it seemed like it was a month!). It was a day we looked forward to all month long. We loved pizza day!

I mean of course, we got to eat cheesy pizza (yumm), but even better than the pizza?

The “lunchroom” desserts that came with it. Also known as the desserts that all the PTA moms would bring in. Enter the giant chocolate chip cookies and the generously frosted chocolate peanut butter bars. Again, yumm!

Today I took inspiration from my grade school days and really thought back to what I loved most about those “lunchroom” peanut bars.

They were doughy, heavy on the peanut butter, and frosted with the most delicious fudgy chocolate frosting. The frosting was a cross between fudge, frosting, and icing. Hard to explain, but I get the feeling many of you know what I’m talking about.

Who else enjoyed a good ole’ chocolate peanut butter bar on pizza day? Any of you? I can’t be alone on this one.

overhead photo of Lunchroom Chocolate Peanut Butter Bars

Lunchroom Chocolate Peanut Butter Bars…the details.

For once, this dessert didn’t take me forever to perfect. Though I did have to make the frosting about four times to get it JUST right.

These bars are easy…so easy…and very hard to mess up.

Start with the peanut cookie base. I used my favorite blondie recipe that’s pretty much foolproof. It doesn’t even require a mixer, just mix with a spoon and bake. So simple. As soon as the peanut bars come out of the oven, dollop them with a hefty amount of creamy peanut butter. The key is to add the peanut butter while the bars are still warm. The heat from the bars allows the peanut butter to melt into one even layer and make spreading the peanut butter out very simple.

Now let the bars chill completely.

side angled photo of Lunchroom Chocolate Peanut Butter Bars

In the meantime, make the frosting.

I have some words on this frosting.

When I set out to make these I had a picture of the frosting in my head and I needed to recreate that picture. The frosting needed to be thick and fudgy, but yet soft and almost runny. Think of a just set top that has glazed over and stiffened, but then underneath is fudgy, loose frosting.

Very old school, very vintage, that’s what I was going for. Like the kind of frosting your grandma would make.

overhead photo of Lunchroom Chocolate Peanut Butter Bars

Yummm (apparently, this is today’s word of the day. Just go with me on it).

What is the secret?

The mix of ingredients is basic…butter, sugar, cocoa powder, vanilla, and milk.

So what’s the trick? Using warm to almost hot milk. The heat from the milk warms the butter and turns the cocoa powder into a rich creamy chocolate. It’s so hard to explain, but I promise, it’s beyond good. Just sweet enough, extra chocolatey, smooth, and very fudgy.

Once the bars are cooled, just spread the frosting over top. And that’s it, easy.

You can let the frosting set up or just cut and enjoy, preferably with cold milk, because that’s the best pairing with chocolate and peanut butter.

overhead photo of Lunchroom Chocolate Peanut Butter Bars

Nothing too fancy, but all things incredibly delicious.

I know that things look different this year. But whether you or your kids are heading back to the classroom, or just homeschooling, these bars make for the perfect dessert to enjoy anytime, mid-school day, after school, late night. They all work. Just bake, eat, and enjoy all the deliciousness.

And if your kids are home, these are easy enough for them to help bake up too!

side angled photo of Lunchroom Chocolate Peanut Butter Bars

Looking for easy “lunchroom” style back to school desserts? Here are a few ideas: 

Crinkle Top Brownies

Chocolate Peanut Butter Pretzel Blondies

Giant Salted Espresso Hot Fudge Cookies

Lastly, if you make these lunchroom chocolate peanut butter bars be sure to leave a comment and/or give this recipe a rating! Above all, I love to hear from you guys and always do my best to respond to each and every comment. And of course, if you do make this recipe, don’t forget to tag me on Instagram! Looking through the photos of recipes you all have made is my favorite!

Lunchroom Chocolate Peanut Butter Bars.

Prep Time 20 minutes
Cook Time 20 minutes
Cooling Time 1 hour
Total Time 1 hour 40 minutes
Servings: 24 bars
Calories Per Serving: 253 kcal

Nutritional information is only an estimate. The accuracy of the nutritional information for any recipe on this site is not guaranteed.

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  • 1. Preheat the oven to 350 degrees F. Line a 9x13 inch baking dish with parchment paper.
    2. In a microwave safe bowl, melt together the butter and 1/2 cup peanut butter, stirring every 30 seconds until melted. Stir in the brown sugar, sugar, eggs, and vanilla. Add the flour, baking powder, and salt.
    3. Press/spread the dough out into the prepared dish. Transfer to the oven and bake for 18-22 minutes, until just set in the center. Remove from the oven and dollop tablespoon size spoonfuls of the peanut butter over the bars, lightly spreading the peanut butter in an even layer. Let cool completely.
    4. To make the frosting. Add the butter, 2 cups powdered sugar, cocoa powder, vanilla, and 1/4 cup warm milk to the bowl of a stand mixer. Beat until smooth, adding additional warm milk until the frosting becomes thicker, but still drizzly. Taste, adding more sugar if needed. Spread the frosting over the bars. Let set for 1-ish hour...or slice, snack, and enjoy!


To Make Gluten Free: Use an equal amount of your favorite gluten free flour blend in place of the all-purpose flour. I recommend Cup4Cup gluten free flour.
Storing: these bars keep well for 3-4 days at room temperature or in the fridge. 
To cool the bars quickly for frosting: place in freezer for 15 minutes. Remove and frost.
To Bring Eggs to Room Temperature: place the eggs in a bowl and fill with warm water. Let sit 5 minutes.
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  1. 5 stars
    These are so dang good! Creamy peanut butter, rich chocolate frosting, and nice hint of salt from the butter. Absolutely perfect.

    1. Hey Taylor,
      Awesome!! I am thrilled to hear that this recipe was a winner, thanks a bunch for making it! xTieghan

  2. I have a couple questions. So only 1/2 cup of the peanut butter goes into the actual batter, then 1 1/2 cups gets spread on top? Or did I read the recipe wrong?
    Also, when you say the icing is “drizzly” what do you mean? Mine came out more like. soft peak type icing, even after adding extra milk.
    Sorry if these are really silly questions.

    1. Hi Dakota,
      That is correct, 1/2 cup of the peanut butter goes into the batter in step 2. The remaining 1 1/2 cups of peanut butter will get spread on top in step 3. You will want the icing to be soft, sounds like yours is right:) xTieghan

  3. I am so happy I found this recipe, thank you! It’s absolutely a perfect blend of my favourite things: peanut butter, chocolate, and brownie texture!

  4. 5 stars
    These are delicious! I loved making them because they actually turned out looking like yours and tasting incredible. Your recipes are so fun to make because they turn out great- which is not always the case with the recipes I try on line- lol!
    Proudly bringing these tasty treats to a friend’s house for dessert tonight!
    Thank you!

    1. Hey Julie,
      Wonderful! I am thrilled to hear this recipe was enjoyed, thanks for giving it a go! Happy New Year!🎆 xTieghan

  5. 5 stars
    These are spectacular! Your recipes are so much fun to make because they actually turn out great – which is not always the case for me! I feel like a successful baker with these bars- The frosting is amazing!!! Thanks so much- proudly bringing these to a friends house for dessert tonight! 🙂

    1. Hi Julie,
      Wonderful! I am thrilled to hear this recipe was enjoyed, thanks for giving it a go! Happy New Year!🎆 xTieghan

  6. 5 stars
    delicious and easy! I halved the PB and frosting. The texture is divine. My kids loved them and they were all gone the first day. Will be on my regular rotation of treats! Thanks Tiegan!

  7. 5 stars
    Thank you, Tieghan, for this devine dessert! This is my second time making them. I’m scared I’m going to eat them all before everyone gets home! (I’m 8 months pregnant and eating the entire tray of these little yummies might actually happen.)

    1. Hi Regina,
      I’ve not tried this and I am unsure on how it would affect the batter, so I would just follow the recipe as is. Please let me know if you have any other questions! xTieghan

  8. 5 stars
    These are VERY rich but delicious—I recommend serving up small portions with a glass of milk. We preferred them out of the refrigerator, but they are also nice at room temperature. I will make again!

  9. 5 stars
    Love this recipe. I am cutting back on sugars to help health wise so each new recipe I lower the amount and they are still great .I use either white flour or gluten free also to get little more healthy. Remember the peanut butter has sugar and so does the frosting. Love the frosting recipe too I make it also to have on top of ice cream too! Thanks for sharing and all the work you do!

    1. Hey Theresa,
      Happy Labor Day!🇺🇸 Thanks a lot for giving this recipe a try, I love to hear that it was enjoyed! xTieghan

  10. This were good but not as amazing as everyone said. I used bakers spray instead of parchment paper and we turned out fine. I will say that at 18min the bars were a little firmer than I wanted. I think they certainly tasted better cold.

    They are probably a crowd pleaser for a plain palette but I think Tiegan has really great innovative recipes that my family prefers a bit more. Do not get me wrong, these were realllllly good, but nothing to blow us out of the water.

    They were easy to make so BONUS. I’d certainly make these for kids 🙂

    1. Hey Katie,
      Thanks for giving the recipe a try, sorry they weren’t your favorite. Please let me know if there is anything I can help with! xTieghan

      1. I made these gluten-free and dairy free a couple months ago and they were absolutely incredible! I could have eaten the whole pan myself. I gave them out to friends and neighbors. I actually got a call today from one of the neighbors asking if I could make several trays to bring to the after party of a wedding!

    1. Hey Lauren,
      Do you mean in addition to the cookie part? I haven’t tried this, but you are certainly welcome to test it out! xTieghan

  11. 5 stars
    I don’t know why, but something about how this recipie is written makes it seem like we should put all 2 cups of the PB in with the butter- I’m not sure what, because it’s clearly written correctly, but I even reread the recipe as I was doing it and I still made that mistake. It seems like several other people did as well. I can tell that the bars would’ve been delicious, but mine were so overly peanut buttery that I couldn’t eat them. The frosting is delicious, and I’m going to have to try again because I really want these. I’d suggest editing the ingredients list to indicate that 1 1/2 of the peanut butter should be reserved.

    1. Hey Kaci,
      Thanks for giving the recipe a try, so sorry for any confusion here. I am really not sure how else to write it besides only using 1/2 cup of peanut butter in step 2 and the remaining peanut butter in step 3. xTieghan

        1. Hey Courtney,
          So sorry to hear this, but even as Kaci noted the recipe is written correctly, so there really isn’t much I can do. xTieghan

          1. I’ve seen recipes write “2 cups pb, divided” before. The “divided” gives me a heads up, which I find very helpful. Perhaps writing that? I haven’t these yet, but I will soon! Thanks!

    1. Hey Lilly,
      Fantastic! Thanks a lot for giving this recipe a try, I am so glad it was enjoyed! Have a wonderful holiday weekend 🇺🇸 xTieghan