Peanut butter enthusiasts will find these double peanut better bars a heavenly treat. Combining the richness of peanut butter cookies with a luscious and creamy peanut butter frosting, these bars are a decadent dessert that promises to satisfy your sweet tooth and peanut butter cravings in each and every bite.

Peanut butter has always been a staple in my kitchen, and these double peanut butter bars are a recipe close to my heart. They remind me of cozy afternoons spent baking with my kids, all of which are avid peanut butter connoisseurs by the way. They simply can’t get enough of these tasty treats. In their opinions, peanut butter + even more peanut butter = Perfection!

Double peanut butter bars being put on a plate

The chemistry of peanut butter bars

Baking with peanut butter is an interesting culinary adventure. Peanut butter, rich in fats and proteins, adds moisture, flavor and a dense texture to baked goods. The proteins in peanut butter interact with the gluten flour, creating a tender crumb, while the fats contribute to the richness and mouthfeel of the bars. The balance of sugar, eggs, and peanut butter is key to achieving the perfect texture.

Can I use natural peanut butter in this recipe?

Yes, you can use natural peanut butter, but keep in mind it will alter the texture slightly, due to its different oil content.

How do I bake the bars to perfection?

When the bars turn golden brown and are set in the middle, they are done. Look for visual cues to know when you should take them out of the oven. If the center of the bars lose their shine, they are likely done. To each their own though. Some like it a tad bit undercooked, while others rather all crispy bites. For simplicity, open your oven and tap the pan, if the bars don’t jiggle in the middle, that’s a good sign. You can perform a final test by sticking a toothpick or fork in the middle of the bars, if a few moist crumbs come out, your bars are done. If it comes out unstable in the middle, it needs a bit more time.

Double peanut butter bars stacked on a plate

Can these bars be made gluten-free?

Absolutely! Substitute the all-purpose flour with a gluten-free flour blend to make them suitable for a gluten-free diet. My favorite gluten free baking flour is Bob’s Red Mill.

How long can I store these peanut butter bars?

Store them in an airtight container at room temperature for up to 5 days. You can also freeze them for up to 3 months. I find they usually disappear within those first few days though.

Double peanut butter bars being sliced and put on a plate

What is in peanut butter bars?

Peanut Butter

Adds another fat into your dough or batter that melts easily, allowing your treat to spread a little more. It will also add a creamy texture & rich flavor to your treat.

Unsalted Butter

It is always important to use unsalted butter when baking. If you use salted butter, you have no way of knowing how much salt you are adding to your dough or batter and it will result in an overly salted treat.

Butter adds fats to your dough or batter which helps with moistness, flavor and texture. Butter melts at body temperature, which creates a ‘melt in your mouth’ sensation.

When baking with butter the temperature is important. If the butter is too warm your treat will melt down too fast and overspread in the oven, leaving you with a greasy, flat mess. If your butter is too cold it will have the opposite problem and not melt down enough, leaving your treat too thick.

Brown Sugar

Is granulated sugar with a little molasses mixed in. Molasses is a somewhat smoky flavored natural sweetener, which makes brown sugar a bit sweeter than granulated sugar. Brown sugar draws more moisture into your treat, keeping it softer for longer. It’s also more acidic, which means it will help activate your baking soda.

Granulated Sugar

Adds sweetness, provides a caramelized flavor and crisp texture. Sugar assists with rising when creamed with butter. It helps add moisture to your treat and helps it evenly spread as it melts into a liquid in the heat of the oven. Sugar also helps with naturally preserving your baked treat.


Adds both a protein (egg whites) and fat (egg yolks). The egg whites help with rising because, when foamed, little air pockets get trapped inside the egg white mixture. The water content in egg whites encourages steam while baking, which helps with gluten formation, resulting in nice and thick treats. Egg yolks have emulsifying properties that bring batters and doughs together and help them from collapsing. Unless otherwise specified, always use large eggs.

Vanilla Extract

When using pure vanilla extract, as opposed to imitation flavoring, it will add the deep rich flavor that everybody wants in a treat.

All-purpose Flour

Builds structure as it absorbs liquids and expands. All-purpose flour falls in the middle of bread flour (high in gluten) and cake flour (low in gluten). It’s exactly what it is named, all-purpose, the most universal flour that can be used in most baked goods.

Powdered Sugar

Is just finely ground granulated sugar. It will absorb moisture in your batter or dough. It dissolves easily, ensuring a smooth texture without grittiness. Because it is so fine, it can melt quickly in the oven and spread cookies out more. Powdered sugar also stabilizes and thickens the frosting, thanks to the small amount of cornstarch it contains.


Adjusts the consistency of the frosting, making it a bit more runny.

Freshly baked and frosted double peanut butter bars

How to store peanut butter bars

Store the bars in an airtight container to keep fresh and moist. If you live in a warm climate, you might want to refrigerate them to maintain the frosting’s texture. These bars will keep for up to 5 days.

How to freeze peanut butter bars

You can freeze peanut butter bars for up to 3 months. Place the bars in a single layer in an airtight container, separating layers with parchment paper to avoid sticking.

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Double Peanut Butter Bars

5 from 1 vote
Author: Madison Reid
Prep Time: 15 minutes
Cook Time: 30 minutes
Servings: 24 bars
Perfect for peanut butter lovers everywhere! Peanut butter bars smothered in peanut butter frosting. Rich and delicious.



  • 1 cup unsalted butter
  • 2/3 cup peanut butter
  • 1 cup granulated sugar
  • 1 cup brown sugar
  • 2 eggs
  • 1 tsp vanilla extract
  • 1 tsp baking soda
  • 1/4 tsp fine sea salt
  • 2 cups all-purpose flour


  • 1/3 cup peanut butter
  • 1 cup powdered sugar
  • 1/8 cup milk
  • 1 tsp vanilla extract


  • Preheat oven to 350 degrees
  • In a standing mixer whip butter, peanut butter and sugars for 1 full minute until lighter in color and fluffy
  • Stir in eggs and vanilla until just combined
  • In a separate bowl mix together soda, salt and flour
  • Turn standing mixer on low and slowly pour in dry ingredients
  • Mix just until combined, be careful to not over mix
  • Press cookie mixture into a 9×13 pan and place into oven
  • Bake for 35-40 minutes
  • While cooling, mix all frosting ingredients with a hand mixer
  • While the bars are still warm, pour frosting on top and spread into an even layer
  • Cool for 15 more minutes before slicing


Calories: 263kcal Carbohydrates: 33g Protein: 4g Fat: 14g Saturated Fat: 6g Polyunsaturated Fat: 2g Monounsaturated Fat: 5g Trans Fat: 0.3g Cholesterol: 34mg Sodium: 126mg Potassium: 94mg Fiber: 1g Sugar: 23g Vitamin A: 258IU Calcium: 21mg Iron: 1mg

Have you tried this recipe?

I’d love to see it! Follow @_mrs.madi_ on Instagram and tag your photos with #mrsmadi.