BEST Peanut Butter Bars Recipe (School Cafeteria)
Updated Feb 07, 2025, Published Aug 16, 2022
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Peanut Butter Bars Recipe (School Cafeteria), just like you remember them from elementary school – only better! These peanut butter bars recipes have a soft, chewy peanut butter oatmeal cookie base, chocolate layer, and a super creamy peanut butter butter cream on top. These are the best peanut butter bars EVER!
These yummy, nostalgic peanut butter bars are a classic treat everyone loves!
Why you’ll love this recipe
These peanut butter cookie bars are exactly like the famous school cafeteria bars they used to make in many American schools (elementary and high school)—but better! They’re the perfect after-school snack, or pack them for lunch since the lunch ladies don’t make these in the school cafeteria anymore!
I love that these Lunch Lady Peanut Butter Bars can feed a crowd. I usually have all the ingredients on hand, so if I ever need to make a treat at the last minute, this is my go-to recipe.
Table of Contents
Simple Ingredients
Cookie Layer
- Butter, softened (unsalted butter or salted based on preference)
- Granulated sugar
- Brown Sugar (this was left out of the above photo!)
- Peanut butter
- Eggs, room temperature
- Vanilla extract
- All purpose flour
- Salt
- Baking soda
- Rolled oats
Frosting + Chocolate Layer
Chocolate Layer:
- Semi-sweet chocolate chips
Frosting Layer:
- Powdered sugar
- Smooth peanut butter
- Butter, softened
- Vanilla extract
- Milk
See the recipe card for quantities.
How to make Peanut Butter Bars (Step-by-Step Instructions)
These Peanut Butter Bars are so easy to make, but be warned. Once you have one, you’ll have to have another and possibly half a pan! Don’t say I didn’t warn you.
Preheat oven to 375 degrees f. Grease a “>12×17 inch pan (cookie sheet or jelly roll pan), or use parchment paper to line the pan. Set aside.
Wet ingredients: In a large bowl, cream together on medium speed (using a hand or stand mixer) butter, sugars, peanut butter, eggs, and vanilla until light and fluffy.
Dry ingredients: Sift in flour, salt, baking soda to the creamed mixture.
HINT: I like to sift int the dry ingredients over the top of the wet ingredient bowl for easier clean-up. You can also
Mix the flour mixture well to combine with wet ingredients, scraping down the sides of the bowl once half way through mixing. Add oats. Mix together until combined (cookie dough texture).
Press the dough onto the prepared baking pan sheet until it forms a uniform layer on the bottom of the pan.
Bake at 375 F for about 10 minutes until slightly golden on top. Turn off the oven.
Chocolate Layer:
Sprinkle the chocolate chips on top of the cookie layer and place back in the warm oven (that is turned OFF) for 2 minutes.
Take out the cookie sheet and spread the warm chocolate all over the cookie’s surface with a spatula or knife- creating a smooth thin layer.
Place in fridge to let chocolate layer harden a bit.
Peanut Butter Frosting Layer:
In a medium mixing bowl, cream together (using a hand or stand mixer) the powdered sugar, peanut butter, butter, vanilla, and milk.
The end result should be a uniform creamy peanut butter buttercream.
After the bars and chocolate have cooled completely, gently spread the frosting over the chocolate layer with a spatula.
HINT: Make sure the chocolate layer is cooled completely before adding the peanut butter frosting layer.
Variations
This original recipe, with a chewy peanut butter oatmeal cookie base, will take you right down memory lane. It is the exact recipe my husband’s grandmother made nearly 50 years ago!
- You can also make a graham cracker crumbs crust– if you prefer.
- Try milk chocolate chips instead of semi-sweet if you like a sweeter chocolate taste.
Substitutions
Want to make this gluten-free? Use gluten-free flour and whole oats. No one will ever know!
What can I use instead of peanut butter? If you have a peanut butter allergy, try them with cookie butter instead, and I’m sure they will be delicious!
Sugar variety: Dark brown sugar, golden brown sugar, or white sugar? Which is better for the cookie layer? The original recipe only uses white sugar. If you prefer, you can use a mixture of sugars to deepen the flavor and make the cookie layer more chewy.
How to Store
- Storage: Keep your bars covered in an airtight container on the counter for 5-7 days. Some rimmed baking sheets come with a plastic lid that is perfect for just this sort of occasion. Or, you can just cover them with plastic wrap once the frosting has dried and firmed up a bit. You can also keep the bars in the fridge or freezer and serve them chilled, if you prefer.
- Freezing: These freeze great for 2-3 months. For easier storage, I recommend slicing and separating the bars, then freezing them individually for an hour to set the frosting. Then you can transfer them to a freezer-safe container and stack them so they don’t take up as much space in the freezer.
Best Peanut Butter Bars Recipe
All hands fly for the corner pieces first and the rest is history. The tray is gone by the end of the evening. They will be when you make this recipe too- guaranteed! These peanut butter cookie bars are everyones favorite treat.
Top Tips
- I personally love using creamy peanut butter for the best texture. But if you want to add a little more crunch, you can also use crunchy peanut butter or even just throw a few chopped nuts into the mix.
- Make sure to use old-fashioned oats for the best cookie layer texture and not the quick oats (personal preference)! If quick oats are all you have you can still use them.
- You can use your favorite brand of peanut butter for these peanut butter bars. If you use a natural peanut butter the cookie layer tends to crumble a bit more and remain a little more dry. I have tried it this way and it is still good!
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💙 MADE THIS RECIPE AND LOVED IT? 💙 Please leave a ⭐️STAR rating and COMMENT below- I love connecting with you! Tag me with your creations on Instagram and find me on Pinterest.
Best Peanut Butter Bars Recipe
Ingredients
Cookie Layer:
- ¾ cups butter, softened but not melted
- ¾ cups granulated sugar
- ¾ cups brown sugar
- ¾ cups peanut butter, smooth or crunchy, depending of preference*
- 2 eggs, at room temperature
- 2 tsp vanilla extract
- 1 ½ cups flour
- ½ tsp salt
- ¾ tsp baking soda
- 1 ½ cups rolled oats
Chocolate Layer:
- 1 ½ cups semi-sweet chocolate chips
Frosting Layer:
- 1 cup powdered sugar
- ¾ cup smooth peanut butter
- ¾ cup butter, softened
- 1 tsp vanilla extract
- ¼ cup milk
Instructions
Cookie Layer:
- Preheat oven to 375 degrees f. Grease a 12×17 in cookie sheet or jelly roll pan, or use parchment paper to line the pan. Set aside.
- Wet ingredients: In a large mixing bowl, cream together on medium speed (using a hand or stand mixer) butter, sugars, peanut butter, eggs, and vanilla until light and fluffy.
- Dry ingredients: Sift flour, salt, and baking soda into the creamed mixture. Mix well to combine, scraping down the sides of the bowl once halfway through.
- Add oats. Mix together until combined (cookie dough texture). Press the dough onto the prepared baking pan sheet until it forms a uniform layer on the bottom of the pan.
- Bake at 375 F for about 10 minutes until slightly golden on top. Turn off the oven.
Chocolate Layer:
- Sprinkle the chocolate chips on top of the cookie layer and place back in the warm oven (that is turned OFF) for 2 minutes.
- Take out the cookie sheet and spread the warm chocolate all over the cookie with a spatula or knife- creating a smooth thin layer.
- Place in fridge to let chocolate layer harden a bit.
Peanut Butter Frosting Layer:
- In a medium mixing bowl cream together (using hand or stand mixer) the powdered sugar, peanut butter, butter, vanilla and milk.
- The end result should be a uniform creamy peanut butter buttercream.
- With a spatula gently spread the frosting over the chocolate layer after the bars and chocolate have cooled completely.
Notes
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
Easy and simple recipe to make and are even better the 2nd day.
It’s a family favorite! I’m happy you loved them. Yes, I even freeze them and pull them out 30 minutes before serving and they are delicious!
These are great for baby showers, parties, and more! Enjoy.
Excellent very simple thank you !!
Happy you loved them!
I made this for a baptism gathering and it was the HIT of the party! It was so easy and delicious and just one batch is enough to feed a crowd!
This was hands down one of the best recipes I have made. Everyone was asking for the recipe. Delectable
So happy you loved it! We make it often in our home!
Since my husband has no dentures I should have pulsed the oats. But it was delicious.
Happy you enjoyed them anyway!