Peanut Butter Cookie Bars
Posted Apr 10, 2023, Updated Feb 13, 2024
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These peanut butter cookie bars are easy to make in under 30 minutes. They are gooey, chewy and loaded with peanut butter!
Sometimes the craving for peanut butter cookies strikes, but I don’t want to have to wait for the dough to chill or roll and bake multiple batches of cookies – so I make these peanut butter cookie bars instead!
These peanut butter cookie bars are soft, buttery and absolutely loaded with peanut butter. Ready from start to finish in 30 minutes – they are everything you love about your favorite cookie with a fraction of the work!
Make them your own by adding your favorite mix-ins like chocolate chips or peanut butter chips!
Peanut Butter Cookie Bars: Ingredients & Substitutions
- Salted Butter. Unsalted butter or ghee are good substitutes.
- Creamy Peanut Butter. Choose your favorite creamy peanut butter. Just be aware of the salt content. If using unsalted peanut butter, increase the salt by 1/4 teaspoon.
- Whole Milk. 2% milk, heavy cream or half and half are good substitutes.
- Light Brown Sugar. If you like a little bolder, molasses taste then you can use dark brown sugar.
- Granulated Sugar. White sugar or organic cane sugar are both great options.
- Sea salt. I only ever bake with pure, fine sea salt. If you are using iodized salt I recommend decreasing the amount of salt by half.
- Peanut butter chips. You can omit these, or choose a different mix-in such as chocolate chips, cinnamon chips, etc.
How to Make Peanut Butter Cookie Bars
Let’s walk through this peanut butter cookie bars recipe step-by-step, and don’t forget to watch the video.
Begin by mixing together flour, baking soda, salt, baking powder cinnamon in a medium bowl, then set it aside.
Then, in the bowl of a standing mixer fitted with the paddle attachment, or in a large bowl with a hand-held mixer, cream together butter and peanut butter until smooth.
Next, add the sugars and beat until combined.
Then, add the egg, vanilla and milk and beat for 30-60 seconds on medium-high speed until the mixture is light in color and sugar is dissolved.
Once the mixture is smooth, add the dry ingredients and mix on low speed until combined.
If you want to add some mix-ins, now is the time to do it! Add 1 cup of mix-ins into the dough and stir to combine. Here are some suggestions:
- chocolate chips
- peanut butter chips
- cinnamon chips
- chopped peanuts
- mini peanut butter cups
- Reese’s pieces
Press the dough evenly into the prepared baking dish, then bake in preheated oven for approximately 22-25 minutes until the top is lightly browned.
Let the bars cool in a wire rack (note, they will likely “deflate” a little bit as they cool, that is normal).
Cool, Cut & Serve
Finally, let the peanut butter cookie bars cool for at least 60 minutes. The longer they cool, the better they hold up to cutting.
If you’re just going to serve them warm with vanilla ice cream, then I wouldn’t worry too much about their appearance, because the taste and warm gooey texture is most important in that situation!
Store/Freeze
Store these peanut butter cookie bars in an airtight container in the refrigerator for up to 1 week, or in the freezer for up to 2 months.
Peanut Butter Cookie Bars Recipe FAQs
Yes, double the ingredients and bake the bars in a 9×13″ baking dish for 25 minutes (or until the edges are golden brown and the top is lightly browned and set).
If you double this recipe and make it in a 9×13″ pan, you can make up to 36 bars, depending on the size you cut them.
Yes, they harden as they cool or are stored in the refrigerator.
Yes. Natural peanut butter (with 2 ingredients: peanuts and salt) works well in this recipe. You can also use this homemade peanut butter.
If you’re cutting these to add to a cookie tray or serve to a crowd, here are my tips on getting clean, even squares:
Let the bars cool all completely to room temperature before cutting.
Use a very sharp, long knife.
Dip the knife in warm water and quickly dry it off before the first cut. Then wipe it clean, dip it in warm water, then dry again before each subsequent cut.
Use a ruler to measure equal pieces. If cutting these cookie bars into 16 squares, you’d want each bar to be 2″ x 2.”
They are done when the edges are lightly golden brown and the top is set. They will jiggle slightly when removed from the oven, which gives you the nice gooey center pieces. If you prefer a firmer cookie bar, bake longer.
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Peanut Butter Cookie Bars
Ingredients
- ½ cup salted butter softened
- 1 cup creamy peanut butter
- ½ cup granulated sugar
- ½ cup light brown sugar packed
- 1 Tablespoon whole milk
- 1 teaspoon pure vanilla extract
- 1 egg
- 1 cup all-purpose flour
- ½ teaspoon baking soda
- ¼ teaspoon fine sea salt
- ¼ teaspoon baking powder
- ¼ teaspoon cinnamon optional, but recommended!
- 1 cup peanut butter chips optional or chocolate chips, etc.
Instructions
- Preheat oven to 350 degrees F. Line a 9×9” baking pan with parchment paper and set aside.
- In a medium bowl, mix together flour, baking soda, salt, baking powder cinnamon. Set aside.
- Then, in the bowl of a standing mixer fitted with the paddle attachment, or in a large bowl with a hand-held mixer, cream together butter and peanut butter until smooth.
- Add the granulated sugar and brown sugar and beat until combined.
- Add egg, vanilla and milk and beat for 30-60 seconds on medium-high speed until the mixture is light in color and sugar is dissolved.
- Add the dry ingredients and mix on low speed until combined.
- If desired, add peanut butter chips or desired mix-ins and stir until combined.
- Press the dough evenly into the prepared baking dish, then bake in preheated oven for approximately 22-25 minutes until the top is lightly browned.
- Let the bars cool in a wire rack (note, they will likely “deflate” a little bit as they cool, that is normal).
- Once cooled, cut into 9 or 16 squares and serve.
Video
Notes
- Salted Butter. Unsalted butter or ghee are good substitutes.
- Creamy Peanut Butter. Choose your favorite creamy peanut butter. Just be aware of the salt content. If using unsalted peanut butter, increase the salt by 1/4 teaspoon.
- Whole Milk. 2% milk, heavy cream or half and half are good substitutes.
- Light Brown Sugar. If you like a little bolder, molasses taste then you can use dark brown sugar.
- Granulated Sugar. White sugar or organic cane sugar are both great options.
- Sea salt. I only ever bake with pure, fine sea salt. If you are using iodized salt I recommend decreasing the amount of salt by half.
- Peanut butter chips. You can omit these, or choose a different mix-in such as chocolate chips, cinnamon chips, etc.
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
Not only is this easy and quick, but it may be the best cookie &/or bar I’ve ever made! No joke. I add dark chocolate chips- yum! I stumbled upon this recipe a couple months ago and shave made it 3 times since. I always double the batch because they’re just that good. Thank you!!
LOVE the addition of dark chocolate chips, Dawn! Yum!
I made these for our Veterans meal and they loved them. Quick and easy. a win, win for me.
definately give them a try.
That is so kind of you Linda, what a great treat to make for the men and women who have served our country.
About the 5th time I have made these bars and family and friends love them
These are so delicious! Were a little crumbly when warm but firmed up when I decided to be patient and let them cool! Added a few Reese’s pieces 😀
Can I substitute butter with shortening?
You can if you’d like, although the butter adds great flavor.
Can you add 1 cup of oatmeal to the batter?
Scrumptious! These are exactly what I was hoping for. Great texture, sweet & peanut buttery. Plus so easy to make (I used a whisk instead of a mixer & self rising flour with a touch of cinnamon). Can’t wait to make these for a family get-together! Only downside is having to share….lol
Thank you so much Kate! I’m so glad you love them!