Peanut Butter Cookie Bars

Published Date: May 22, 2023

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Peanut Butter Cookie Bars on a white plate.

These Peanut Butter Cookie Bars are soft, chewy treats that are loaded with chocolate chips, walnuts, and mini Reese’s Peanut Butter Cups! Bake up a salty, sweet batch in just 35 minutes!

Peanut Butter Cookie Bars on a white plate.

Reese’s Peanut Butter Cookie Bars are an easy-to-make dessert that’s great for potlucks, parties, or as a treat to get you through the week! The mixture of salty, sweet, and nutty flavors makes for a cookie bar that’s completely irresistible.

All that’s needed are pantry staples and a few mix-ins! You could even make a batch to freeze in slices!

That way, you can pull one or two out at a time for a sweet treat without making a mess in the kitchen!

Taste: These cookie bars are the most delicious combination of peanut butter and chocolate! The sweet, salty flavor is then complimented by the nutty taste of walnuts that are studded throughout them!

Texture: If you love a texture-rich dessert, then you’re going to LOVE these bars! They’re amazingly soft and chewy with a nice crunch from the walnuts.

For an even tastier texture, bite in these when they’re warm so you can enjoy those pockets of melty chocolate and peanut butter!

Overhead photo of ingredients prepped to make peanut butter cookie bars on a white table.

Ingredients For Peanut Butter Cookie Bars

  • Unsalted Butter
  • Granulated Sugar
  • Light Brown Sugar
  • Large Eggs
  • Vanilla Extract
  • All-Purpose Flour
  • Baking Powder
  • Baking Soda
  • Mini Reese’s Peanut Butter Cups
  • Semisweet Chocolate Chips
  • Chopped Walnuts

The base of this homemade cookie bar recipe is made with pantry staple ingredients. This makes it easy to bake up a batch anytime the desire for a peanut buttery treat hits!

One recipe tip to ensure your cookie bars come out flawlessly is to allow the ingredients to come to room temperature before mixing. This will help the dough mix up easier as well as incorporate much more evenly.

Though the foundation of these bars seems simple, it’s the mix-ins that take them to the next level! These bars are loaded with walnuts, chocolate chips, and chopped-up mini Peanut Butter Cups.

Peanut Butter Cookie Bars on a piece of parchment.

How To Make Reese’s Peanut Butter Cup Cookie Bars Step-by-Step

Step 1: Whisk the flour, baking powder, and baking soda together in a medium mixing bowl.

Step 2: Cream the butter, granulated sugar, and brown sugar using a hand mixer on medium-high speed in a large mixing bowl.

Dry ingredients to make cookies bars in a glass mixing bowl.
Peanut butter, butter, and sugars creamed together in a glass mixing bowl.

Step 3: Mix in the eggs, vanilla extract, and salt until just incorporated.

Step 4: Slowly add in the flour mixture and then mix until a cookie dough consistency is formed.

Eggs being added to peanut butter cookie dough.
Flour being added to peanut butter cookie dough.

Step 5: Fold in the chopped Reeses’s Peanut Butter Cups, semisweet chocolate chips, and chopped walnuts.

Step 6: Press the cookie dough evenly down in the prepared baking pan. Then top it with more chopped Reese’s Peanut Butter Cups, chopped walnuts, and semisweet chocolate chips.

Chocolate chips and peanut butter cups being folded into cookie dough.
Peanut Butter Cookie dough pressed into a pan to make bars.

Step 7: Bake the cookie bars until a toothpick that’s been inserted into the center comes out clean. Next, transfer the pan of bars onto a wire rack to cool completely before cutting and serving!

A glass pan with peanut butter cookie bars in it.

How To Serve Peanut Butter Cup Cookie Bars

To me, anything cookie-related is best enjoyed warm! Those hidden pockets of melted chocolate chips and peanut butter cups just make for a tasty experience.

Of course, any cookie served warm should also be followed up by an ice-cold glass of milk!

For the ultimate dessert, warm up a slice of these cookie bars and top it with vanilla ice cream as well as a dollop of whipped cream!

Storage Instructions

Store these Reese’s Peanut Butter Cup Bars in an airtight container at room temperature to enjoy for up to 3 days.

These Cookie Bars can also be frozen! To do so, wrap them in plastic wrap or tinfoil. Afterward, place the wrapped bars in a Ziploc freezer bag and squeeze out the excess air before sealing.

The frozen bars can then be stored for up to 6 months.

Peanut Butter Chocolate Chip Cookies bars on a white plate.

Reese’s Peanut Butter Cup Cookie Bars Substitutions And Variations

  • Butter – Salted butter can be used in place of unsalted butter as long as you omit the ½ teaspoon of salt.
  • Peanut Butter Cups – Regular-sized peanut butter cups can be used in this recipe instead of the mini version. To do so, just chop them up into smaller chunks first!
  • Peanut Butter Chips – For more peanut buttery flavor, you can replace half of the semisweet chocolate chips with peanut butter chips.
  • Nuts – Feel free to exchange the walnuts for whichever nut you prefer. I think peanuts would be a great addition to these cookie bars!
  • Peanut Butter Drizzle – Push these bars over the edge by giving them a peanut butter drizzle finish! Simply microwave peanut butter in a heat-safe dish and then drizzle it over the cooled bars. Allow the peanut butter drizzle to set before slicing and enjoying!
Overhead photo of peanut butter cookie bars cup up on a table.

Peanut Butter Cookie Bars FAQS

How Many Peanut Butter Cookie Bars Does This Recipe Yield?

I make this recipe in a 9×13-inch baking dish and can comfortably slice and serve 15 slices.

Can I Reheat Cookie Bars?

Yes, and I’d encourage you to do so, especially if you’re serving with a scoop of ice cream! Simply reheat an individual slice by popping it in the microwave for 15 seconds.

Why Did My Cookies Bars Come Out Dry And Crumbly?

Dry, crumbly cookies are often the result of either being baked for too long or too much flour accidentally being added to the recipe.

When baking these bars, be sure to cook them at 350 degrees F for about 30 to 35 minutes. Around the 30-minute mark, check the bars by inserting a toothpick into the center of them.

If the toothpick comes out clean, then the bars are done baking. If not, slide them back in the oven for just a minute or two longer.

As for the possibility of too much flour being added to the cookie recipe, be careful not to pack the flour into the measuring cup.

Instead, first, fluff the flour and then scoop the fluffed flour into the measuring cup.

How Come The Center Of My Cookie Bars Isn’t Cooked All The Way?

If the center of your bars isn’t cooked, then they may have been removed from the oven too early. Or they were cooked at too low of a temperature.

Peanut Butter Cookie Bars on a white plate.
Peanut Butter Cookie Bars on a white plate.

Reese’s Peanut Butter Cup Cookie Bars

These cookie bars are soft and chewy with a little crunch from the nuts. It’s the perfect combination of peanut butter and chocolate. Each bite is loaded with Reese’s peanut butter cup minis, semisweet chocolate chips, and walnuts.
5 from 1 vote
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Course: Dessert
Cuisine: American
Prep Time: 10 minutes
Cook Time: 35 minutes
Cooling Time: 1 hour
Total Time: 1 hour 45 minutes
Servings: 15 people
Calories: 544kcal


  • 9×13-inch baking pan
  • Parchment paper (optional for easier removal)
  • Mixing bowls
  • Hand mixer


  • 3 cups all-purpose flour
  • ½ teaspoon baking powder
  • ½ teaspoon baking soda
  • ½ teaspoon salt
  • 1 cup unsalted butter softened at room temperature
  • 1 cup light brown sugar packed
  • ¾ cup granulated sugar
  • 2 large eggs
  • teaspoons pure vanilla extract
  • cups chopped Reese’s peanut butter cups minis divided
  • 1 cup semisweet chocolate chips divided
  • ½ cup chopped walnuts or peanuts, optional


  • Preheat the oven to 350°F. Lightly grease the bottom of a baking pan and line it with parchment paper. Set it aside.
  • In a medium mixing bowl, whisk together 3 cups all-purpose flour, ½ teaspoon baking powder, ½ teaspoon baking soda, and ½ teaspoon salt. Set aside.
  • In a large mixing bowl or stand mixer fitted with a paddle attachment, cream together 1 cup unsalted butter, 1 cup light brown sugar, and ¾ cup granulated sugar at medium-high speed for about 2 minutes.
  • Add in 2 large eggs, 1½ teaspoons pure vanilla extract, and mix at medium speed until just incorporated.
  • Slowly add the flour mixture and mix until you get a soft dough consistency. Then fold in 1 cup of the 1½ cups chopped Reese’s peanut butter cups minis, ¾ cup of the 1 cup semisweet chocolate chips, and ½ cup chopped walnuts until evenly distributed in the dough. Set the remaining aside for topping.
  • Press the cookie dough into an even layer in the prepared baking pan. Sprinkle and gently press the remaining toppings into the top of the dough.
  • Bake for 30 to 35 minutes or until a toothpick inserted in the center comes out clean.
  • Allow the bars to cool in the pan on a wire rack before cutting them into squares and serving.


You can use regular-sized Reese’s peanut butter cups if you like. Just roughly chop them into smaller chunks.
Swap out the nuts with whichever is your favorite.
Make sure that the ingredients come to room temperature before mixing. This will help it mix easier and incorporate much more evenly.


Calories: 544kcal | Carbohydrates: 66g | Protein: 8g | Fat: 29g | Saturated Fat: 14g | Polyunsaturated Fat: 4g | Monounsaturated Fat: 9g | Trans Fat: 1g | Cholesterol: 57mg | Sodium: 245mg | Potassium: 241mg | Fiber: 3g | Sugar: 42g | Vitamin A: 432IU | Vitamin C: 0.1mg | Calcium: 64mg | Iron: 3mg

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Gabby Hubbell Family Busy Family Recipes Author

From one busy family to another, I see you.

Hi, I’m Gabby! From crockpots to one-pot recipes, we’re eager to make dinner time a breeze for you and your family. Follow along for recipes even the pickiest of eaters will enjoy time and time again!
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