There’s something undeniably magical about the combination of peanut butter and chocolate. It’s a pairing that speaks directly to the soul of dessert lovers everywhere. This recipe showcases the classic duo, offering a rich, chewy brownie base topped with a smooth, nutty peanut butter frosting that’s sure to delight any crowd. Check out these Peanut Butter Caramel Cookies if you aren’t in love with brownies.

Let’s embark on a tasty journey to explore the creation of these irresistible brownies, delving into their chemistry, detailed recipe steps, and storage tips to ensure you can recreate this masterpiece at home.

As a dessert connoisseur, I’ve always believed that brownies represent the epitome of indulgence, and the addition of peanut butter only elevates this treat to new heights. This recipe is a culmination of my love for both ingredients, designed to create a dessert that’s both comforting and sophisticated. Baking these brownies is not just about following steps; it’s about weaving together flavors and textures to craft a dessert that’s truly more than the sum of its parts. If you love these brownies, you should check out my Brownie Board.

Peanut Butter Chocolate Brownies freshly made

The Chemistry of Peanut Butter Chocolate Brownies

The foundation of these brownies lies in the perfect balance between fat, sugar, and flour. The unsalted butter and eggs provide richness and moisture, while the granulated sugar ensures a tender texture. Cocoa powder offers deep chocolate notes, which are enhanced by the melty semi-sweet chocolate chips. The real magic happens with the additional of cornstarch, which softens the protein in the flour, resulting in a chewier brownie. The peanut butter frosting, a creamy concoction of butter, peanut butter, and powdered sugar, creates a smooth and luscious layer that complements the dense chocolate base beautifully.

Why add cornstarch to brownies?

Cornstarch is the secret to achieving that coveted chewy texture. It interferes with protein formation in the flour, ensuring the brownies stay moist and tender. Who doesn’t love a soft and dense brownie?!

How do you know when the brownies are perfectly baked?

The key is to look for a top that’s set and no longer shiny. indicating the brownies are cooked through but still moist inside. A toothpick inserted should come out with a few moist crumbs for the perfect texture.

Peanut Butter Chocolate Brownies freshly made

Can the brownie batter be made in advance?

Yes, the batter can be prepared and stored in the refrigerator overnight. However, let it come to room temperature before baking to ensure even cooking.

How long does the peanut butter frosting last?

When stored properly in an airtight container in the refrigerator, the frosting can last up to a week. Always bring it to room temperature and give it a quick whip before using to restore its creamy texture.

What is in peanut butter chocolate brownies?

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.

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.

Cocoa Powder

Provides a rich, sweet chocolate flavor. Creates a dark brown color in your treat. Absorbs water in your batter or dough at the same rate as flour. That means, if you add too much, you could end up with a dried, crumbly finished product.

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.

Fine Sea Salt

Enhances flavor, adds balance, masks any bitter flavors. Salt is the most powerful and oldest preservative. Always make sure to use fine sea salt so it melts down at the right speed in the heat of the oven. If you use larger granule salt, it will not melt down fully when baked and will leave salt crystals throughout your treat, making it crunch like you dropped it into sand.

Baking Soda

Elevates the pH level of your batter or dough. It increases the spread in your treat and encourages browning, which gives the crispy outside and soft inside texture that everyone loves. Baking soda needs both an acid and a liquid to react. Things that will activate your baking soda are: vinegar, fruit juice, molasses, brown sugar, tartar, buttermilk and sour cream. Baking soda only reacts once, which is right when it’s mixed into your batter or dough. The soda creates little air bubbles all throughout your treat. When the air bubbles get heated up in the oven, they expand.


Helps create a crumbly tender texture to toppings. Softens cookies, brownies and cakes. And it can also thicken sauces and fillings.

Chocolate Chips

Is a form of chocolate. Chocolate chips are not pure chocolate, they are typically made up of cocoa, sugar, emulsifier and vanilla. Chips are good for baking because they do not melt completely in the oven like pure chocolate would. That way you get confined pockets of chocolate throughout your treat.

Unsalted butter

Often the main ingredient of frosting, it adds structure to your buttercream. It also adds a smooth and velvety texture. Butter melts at body temperature, so it will make your frosting have a melt-in-your-mouth sensation.

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.

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.

Heavy Whipping Cream

Makes a softer, more spreadable frosting. When melted with chocolate it adds more fat and moisture to the mixture, resulting in a silkier blend.

Peanut Butter Chocolate Brownies freshly made

Storage Tips

Store the frosted brownies in an airtight container in the refrigerator for up to 5 days. For the best texture, allow them to come to room temperature before serving. The unfrosted & frosted brownies can also be frozen for up to 3 months; wrap them tightly in plastic wrap and foil. Thaw the brownies overnight in the refrigerator and add the frosting before serving if they’re unfrosted.


Both the frosted and unfrosted brownies freeze well. Wrap the unfrosted brownies tightly in plastic wrap and aluminum foil. For frosted brownies. freeze them uncovered first to set the frosting, then wrap as mentioned. They can be frozen for up to 3 months.

Making Ahead

Preparing the brownies a day ahead is a great way to divide the baking process. Bake the brownies, let them cool, and store them covered at room temperature. Make the frosting on the day of serving for the freshest taste.

Peanut Butter Chocolate Brownies freshly made

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Why make peanut butter chocolate brownies?

Embarking on the journey to create these peanut butter chocolate brownies not only satisfies your sweet tooth but also offers a delightful experience in the kitchen, blending the rich flavors of chocolate and peanut butter into a dessert that’s sure to become a staple for all your gatherings.

Recipes You May Love

Peanut Butter Chocolate Brownies

Author: Madison Reid
Prep Time: 15 minutes
Cook Time: 35 minutes
Servings: 16
These chewy double chocolate brownies topped with luscious nutty peanut butter frosting are a major crowd pleaser!


Chewy Double Chocolate Brownies

  • 1 cup unsalted butter
  • 2 cups granulated sugar
  • 4 eggs
  • 2 tsp vanilla extract
  • 1/2 cup cocoa powder
  • 1 1/2 cup all-purpose flour
  • 1 tsp fine sea salt
  • 1/8 tsp baking soda
  • 1 tbsp cornstarch
  • 11 ounces semi sweet chocolate chips **1 bag

Peanut Butter Frosting

  • 1 cup unsalted butter
  • 1 cup creamy peanut butter
  • 5 cups powdered sugar
  • 1 tsp vanilla extract
  • 1 tbsp heavy whipping cream


Chewy Double Brownies

  • Preheat your oven to 350 degrees
  • In a standing mixer combine the room temperature butter and granulated sugar, mix until combined and then turn the speed up to high and whip for 1-2 minutes until the mixture is lighter in color and texture
  • Turn the mixer off and add the eggs and vanilla extract to the mixer. Turn it back on low speed and mix until combined.
  • Turn the mixer off and add the cocoa powder, flour, salt, baking soda, and cornstarch. Mix on low until combined.
  • Pour the bag of semi sweet chocolate chips into the batter and fold in.
  • Pour and spread the batter into a greased and parchment paper lined 9×13 pan
  • Bake the brownies for 35-37 minutes until the top of the brownies are no longer shiny in the center.
  • Remove the brownies and allow them to cool. While the brownies are cooling, whip up the frosting.

Peanut Butter Frosting

  • In a standing mixer add the butter and peanut butter, mix until combined.
  • Add in the powdered sugar and mix until combined and clumpy
  • Add the cream and vanilla extract, mix until smooth
  • Once smooth turn the mixer on high and whip for 1-2 minutes until lighter in color and texture.
  • Spread or pipe the peanut butter frosting on top of the chewy double chocolate brownies.


Calories: 726kcal Carbohydrates: 87g Protein: 8g Fat: 41g Saturated Fat: 21g Polyunsaturated Fat: 3g Monounsaturated Fat: 13g Trans Fat: 1g Cholesterol: 104mg Sodium: 246mg Potassium: 280mg Fiber: 4g Sugar: 71g Vitamin A: 792IU Vitamin C: 0.01mg Calcium: 40mg Iron: 3mg

Have you tried this recipe?

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

Peanut Butter Chocolate Brownies freshly made