If you’re a fan of rich, fudgy chocolate and the creamy, nutty goodness of peanut butter, then this Chocolate Brownie Cake with Peanut Butter Frosting might just become your new favorite dessert. This indulgent treat combines the dense, chewy texture of a brownie with the structure and height of a cake, resulting in a decadent hybrid that satisfies every chocolate lover’s dream. Topped with a silky-smooth peanut butter frosting that’s both salty and sweet, this dessert is a flavor-packed showstopper perfect for any occasion.

Unlike a traditional layered cake, brownie cake offers a slightly gooier bite and a deeper chocolate intensity. Pairing it with peanut butter frosting creates the ultimate sweet-savory balance, reminiscent of a peanut butter cup but in cake form. Whether you’re baking for a birthday, holiday celebration, or simply craving a homemade treat, this recipe delivers on both taste and texture.

What makes this dessert even more appealing is how approachable it is. You don’t need any fancy equipment or hard-to-find ingredients—just a love for chocolate, peanut butter, and a desire to impress your taste buds. You can customize it with chocolate chips, drizzle it with ganache, or top it with crushed peanuts for added crunch.

In this guide, we’ll walk you through everything you need to know to make the perfect Chocolate Brownie Cake with Peanut Butter Frosting—from ingredients and baking tips to storage and serving suggestions. Get ready to bake your new go-to dessert!

Why Chocolate and Peanut Butter Are a Perfect Match

Few flavor pairings have stood the test of time like chocolate and peanut butter. Whether in candies, cookies, or cakes, this iconic duo continues to win hearts (and taste buds) around the world. But what exactly makes these two ingredients such a perfect match?

It all comes down to balance and contrast. Chocolate—especially dark or semi-sweet varieties—brings a deep, rich bitterness with a hint of sweetness. Peanut butter, on the other hand, is naturally salty, nutty, and creamy. When combined, they create a flavor profile that hits all the right notes: sweet, salty, bitter, and umami. This sensory balance is one of the main reasons our brains find the combo so satisfying.

From a scientific standpoint, peanut butter contains fat and protein, which helps mellow out the boldness of chocolate. Meanwhile, chocolate enhances the nutty depth of peanut butter, adding complexity with its roasted cocoa notes. The two also share complementary textures—smooth and creamy frosting paired with dense, fudgy cake creates an irresistible mouthfeel.

There’s also a nostalgia factor at play. For many, chocolate and peanut butter bring back memories of childhood treats like peanut butter cups or homemade desserts. This emotional connection only enhances the enjoyment.

Culturally, this combo has become a staple in American desserts. It’s frequently used in baked goods, ice creams, milkshakes, and candy bars because of its widespread appeal. When incorporated into a dessert like a brownie cake, the results are indulgent, comforting, and universally loved.

In short, chocolate and peanut butter work together because they offer both contrast and harmony. They elevate each other, creating a taste experience that’s bold, balanced, and completely crave-worthy. That’s why, when it comes to desserts, few combinations come close to the magic of chocolate and peanut butter.

Key Ingredients Breakdown

Creating a rich and flavorful chocolate brownie cake with peanut butter frosting starts with quality ingredients. Each component plays a specific role in achieving the dense, fudgy texture of the cake and the smooth, creamy consistency of the frosting.

For the Brownie Cake

Unsweetened Cocoa Powder: Provides a deep chocolate flavor. Dutch-processed or natural cocoa can be used, but each will slightly affect the taste and color.

Dark Chocolate (chopped or chips): Melting real chocolate into the batter boosts richness and contributes to the cake’s moist, gooey texture.
Butter: Adds fat for moisture and richness. Unsalted butter is preferred for better control over the saltiness.
Granulated Sugar: Sweetens the batter and helps create that classic brownie crackle on top.

Brown Sugar (optional): Adds a subtle molasses flavor and enhances chewiness.
Eggs: Bind the ingredients and provide structure while contributing to the cake’s dense texture.
All-Purpose Flour: The main dry ingredient that gives the cake its form. Use sparingly to keep the texture moist and not cakey.

Vanilla Extract: Enhances the chocolate flavor with a warm, aromatic note.
Salt: Balances sweetness and intensifies the chocolate.

For the Peanut Butter Frosting

Creamy Peanut Butter: The star ingredient for the frosting. Use commercial peanut butter (like Jif or Skippy) for consistent texture and sweetness.

Powdered Sugar: Sweetens the frosting and provides structure.
Butter: Helps create a creamy base and gives the frosting its smooth finish.
Heavy Cream or Milk: Adjusts the consistency, making the frosting easier to spread.

Vanilla Extract: Adds depth and enhances the peanut butter flavor.
Salt (optional): A pinch can help balance the sweetness.

Substitutions and Variations

Gluten-Free: Use a 1:1 gluten-free baking flour blend.

Vegan: Substitute eggs with flaxseed meal or applesauce, and use vegan butter and dairy-free milk.
Nut-Free Option: Replace peanut butter with sunflower seed butter or cookie butter for a similar texture with a different flavor.

Equipment You’ll Need

To ensure a smooth baking process, it’s important to have the right tools. Most of these items are standard kitchen essentials.

Mixing Bowls: One for the wet ingredients and one for the dry. Glass or stainless steel works best.
Hand Mixer or Stand Mixer: Needed for making the frosting and can be helpful when mixing the brownie batter.

Spatula: Silicone spatulas are perfect for folding batter and scraping down the sides of bowls.
Whisk: Useful for combining dry ingredients and ensuring there are no lumps.
Measuring Cups and Spoons: Precision is key when baking. Use dry and liquid measuring tools accordingly.

9-inch Cake Pan or Square Pan: A metal pan gives the best heat distribution. Line with parchment paper for easy removal.
Parchment Paper: Prevents the cake from sticking and helps with an easy release.
Offset Spatula: Ideal for spreading frosting evenly across the cake surface.

Cooling Rack: Ensures the cake cools evenly and prevents overbaking from residual heat.

Having these tools ready before you start makes the entire process smoother and more enjoyable.

How to Make Chocolate Brownie Cake with Peanut Butter Frosting

Creating this decadent dessert is simpler than it looks. Follow these step-by-step instructions to ensure a rich, moist brownie cake topped with creamy peanut butter frosting.

Step 1: Preheat and Prepare

Preheat your oven to 350°F (175°C). Line a 9-inch round or square cake pan with parchment paper and lightly grease the sides. This ensures the cake comes out cleanly after baking.

Step 2: Make the Brownie Batter

In a heatproof bowl, melt 1 cup of unsalted butter and 6 ounces of dark chocolate together. Use a microwave in 20-second bursts or a double boiler on the stovetop. Stir until smooth and let cool slightly.

In a large bowl, whisk together 1¼ cups of granulated sugar and ½ cup of brown sugar with 3 large eggs and 1 teaspoon of vanilla extract. Beat until the mixture is light and slightly thickened. Slowly pour in the cooled chocolate mixture and stir to combine.

Sift in ¾ cup of all-purpose flour, ½ cup of unsweetened cocoa powder, and ½ teaspoon of salt. Fold gently until no dry spots remain. Do not overmix.

Step 3: Bake

Pour the batter into your prepared pan and smooth the top. Bake for 25–30 minutes or until a toothpick inserted in the center comes out with moist crumbs. Let the cake cool completely in the pan on a wire rack before frosting.

Step 4: Make the Peanut Butter Frosting

In a large mixing bowl, beat ½ cup of softened unsalted butter and ¾ cup of creamy peanut butter until fluffy. Add 1½ cups of powdered sugar gradually, mixing until smooth. Add 2–3 tablespoons of heavy cream or milk, one tablespoon at a time, until the frosting reaches a spreadable consistency. Mix in ½ teaspoon of vanilla extract.

Step 5: Frost the Cake

Once the cake has cooled, use an offset spatula to spread the peanut butter frosting evenly across the top. For added texture or decoration, sprinkle chopped peanuts or drizzle melted chocolate over the frosting.

Pro Tips for the Best Results

Use Room Temperature Ingredients: Butter, eggs, and peanut butter mix more evenly when they’re not cold, resulting in a smoother batter and frosting.
Don’t Overmix the Batter: Once the dry ingredients are added, fold gently. Overmixing can lead to a tough or cakey texture, rather than a dense, fudgy one.
Check for Doneness Early: Since oven temperatures vary, start checking at the 25-minute mark. Look for moist crumbs on a toothpick, not raw batter or a dry toothpick.

Cool Completely Before Frosting: Frosting a warm cake will melt the peanut butter frosting and ruin the texture. Be patient and let the cake cool fully on a rack.
Use Quality Chocolate and Peanut Butter: These two ingredients carry the flavor. Choose high-quality chocolate (at least 60% cacao) and creamy peanut butter without added sugar or oil for best results.
Sift the Powdered Sugar: For a lump-free frosting, sift the powdered sugar before adding it to the peanut butter mixture.

Chill the Frosted Cake Briefly: If the frosting is too soft or you’re planning to slice it cleanly for serving, a short chill in the fridge (about 20–30 minutes) will firm it up without drying out the cake.

Variations to Try

This recipe is versatile and easy to customize. Here are some popular variations to consider:

1. Add Chocolate Chips or Chunks

Mix ½ cup of semi-sweet or milk chocolate chips into the batter before baking for pockets of melted chocolate throughout the cake.

2. Crunchy Peanut Butter Frosting

Swap creamy peanut butter for crunchy to add texture and a nutty bite to every slice.

3. Salted Caramel Swirl

Before baking, drizzle salted caramel over the batter and gently swirl with a knife. This adds a sweet and salty contrast to the dense chocolate.

4. Turn it into Cupcakes or Bars

Use a muffin tin to make brownie cupcakes, reducing the baking time to 15–18 minutes. Or bake in a rectangular pan and cut into squares for brownie bars.

5. Banana Brownie Cake

Add 1 mashed ripe banana to the batter for added moisture and a subtle banana flavor that complements both chocolate and peanut butter.

6. Espresso Infusion

Mix 1 teaspoon of instant espresso powder into the batter to intensify the chocolate flavor without making it taste like coffee.

7. Nut-Free Frosting Alternative

If you need to avoid nuts, use cookie butter or sunflower seed butter in place of peanut butter. The texture stays creamy, and the flavor adds a new twist.

These variations allow you to experiment while maintaining the essence of the original recipe. Don’t be afraid to get creative and make it your own.

How to Store and Freeze

Proper storage is essential to maintain the freshness and texture of your brownie cake.

At Room Temperature

If you plan to eat the cake within 2–3 days, you can store it at room temperature. Place it in an airtight container or cover it tightly with plastic wrap to prevent it from drying out. Keep it in a cool, dry place away from direct sunlight.

In the Refrigerator

For longer storage (up to 5 days), refrigerate the cake. The frosting will firm up in the fridge, so allow the cake to come to room temperature for about 30 minutes before serving for best texture.

Freezing Instructions

You can freeze the cake, either frosted or unfrosted. To freeze:

Wrap the entire cake or individual slices tightly in plastic wrap.
Place the wrapped cake into a freezer-safe container or zip-top bag.
Label with the date and freeze for up to 2 months.

To thaw, move the cake to the refrigerator overnight, then bring it to room temperature before serving. Avoid microwaving to thaw, as it can make the cake rubbery and melt the frosting unevenly.

Serving Suggestions

This chocolate brownie cake with peanut butter frosting is rich and satisfying on its own, but thoughtful serving ideas can elevate the experience.

With Ice Cream

A scoop of vanilla or coffee ice cream on the side adds a creamy contrast to the dense cake. Drizzle with chocolate syrup for a decadent dessert plate.

With Fresh Fruit

Serve with sliced bananas or strawberries for a refreshing and slightly tart counterpoint to the richness of the cake.

As a Birthday Cake

This brownie cake makes an excellent birthday treat. Add colorful sprinkles, chocolate curls, or edible gold flakes for a festive touch.

Warmed Slightly

Warm individual slices in the microwave for 10–15 seconds before serving. This softens the brownie base and slightly melts the frosting for a gooey, indulgent bite.

Pairing Beverages

Pair with a cold glass of milk, a cup of coffee, or even a dark stout or porter beer for an adult twist. The nutty and chocolate flavors complement roasted drinks exceptionally well.

No matter how you serve it, this dessert is guaranteed to impress guests and satisfy any sweet tooth.

Nutritional Breakdown

The following values are approximate and based on a standard 9-inch cake cut into 12 slices. Ingredients and serving sizes may affect actual nutrition.

Calories: 420 per slice
Total Fat: 26g
Saturated Fat: 12g

Cholesterol: 65mg
Sodium: 220mg
Total Carbohydrates: 42g

Sugars: 30g
Protein: 6g
Fiber: 2g

Allergen Information

Contains: Peanuts, dairy, eggs, wheat (gluten)
Can be made gluten-free or dairy-free with substitutions

This dessert is indulgent and best enjoyed in moderation. For those watching their intake, you can reduce the sugar slightly in both the cake and frosting or opt for smaller serving sizes.

If you follow a special diet, there are ways to adapt this recipe with alternative ingredients like almond flour, plant-based butter, or sugar-free sweeteners. Always check product labels for allergen warnings if you’re baking for someone with sensitivities.

Frequently Asked Questions (FAQs)

1. Can I use natural peanut butter in the frosting?
Yes, but be aware that natural peanut butter tends to separate and can make the frosting oily or too soft. If you use it, stir it well and reduce the added cream or milk to maintain structure.

2. What’s the difference between a brownie cake and regular brownies?
A brownie cake is typically thicker and baked in a round or cake pan, giving it a more cake-like appearance while retaining the dense, fudgy interior of classic brownies. It’s ideal for slicing like a traditional cake.

3. Can I use a boxed brownie mix instead of making it from scratch?
Yes, you can use a boxed brownie mix as a shortcut. Just be sure to adjust baking times based on the instructions and cool the cake fully before frosting.

4. How far in advance can I make this cake?
You can bake the cake a day ahead and store it covered at room temperature. The frosting can also be made in advance and stored in the refrigerator, then brought to room temperature before spreading.

5. How can I make this cake less sweet?
Reduce the sugar in the brownie batter by ¼ cup and use less powdered sugar in the frosting. You can also add a pinch of salt or use dark chocolate with higher cacao content to balance sweetness.

Chocolate Brownie Cake with Peanut Butter Frosting

Author: Hamza

Print Recipe

Description

This Chocolate Brownie Cake with Peanut Butter Frosting is the ultimate dessert mashup—dense, fudgy brownie meets soft, sliceable cake, all topped with a rich, creamy peanut butter frosting. It’s easy to make, intensely chocolatey, and perfectly balanced with the sweet-salty depth of peanut butter. Whether you’re baking for a party, a birthday, or just a chocolate craving, this cake is sure to impress and satisfy. Make it from scratch for full control over flavor and texture, or use your favorite boxed brownie mix for a shortcut. Either way, this dessert delivers big flavor with every bite.

Ingredients

Scale

For the brownie cake layers:

1 stick (113 grams) unsalted butter
8 ounces (227 grams) semisweet baking chocolate, chopped

1 cup (200 grams) granulated sugar
2/3 cup (133 grams) dark brown sugar
3/4 cup (95 grams) all-purpose flour

1 cup (85 grams) unsweetened natural cocoa powder
3/4 teaspoon baking powder
1/2 teaspoon salt
5 large eggs, at room temperature
1/2 cup fresh vegetable oil
1 teaspoon vanilla extract

For the peanut butter frosting:

2 sticks (227 grams) unsalted butter, at room temperature
1 cup (270 grams) creamy conventional peanut butter
1 teaspoon vanilla extract
1/8 teaspoon fine salt
2 1/2 cups (313 grams) powdered sugar, sifted

For the chocolate drip:

4 ounces (113 grams) semisweet or bittersweet chocolate, finely chopped
1/2 cup heavy cream
Chopped peanut butter cups, optional

Instructions

Preheat the oven to 350°F. Grease and line three 6-inch cake pans with parchment paper.
In a heat-safe bowl, combine the butter and chocolate and microwave for 45 seconds. Stir and continue to heat in 30-second bursts, stirring between bursts, until melted and smooth. Whisk in the sugars until combined. Let cool.
In a small bowl, whisk together the flour, cocoa powder, baking powder, and salt.
To the cooled chocolate mixture whisk in the eggs, one at a time, Whisk vigorously for 30 seconds until very well combined. Add in the oil and vanilla and whisk until combined. Add the dry ingredients and gently fold to combine.
Divide the batter between the three cake pans, and tap on the counter to prevent air bubbles.
Bake for 25 to 30 minutes, or until the tops are dry and a cake tester inserted in the middle comes out with a few crumbs attached. Be sure not to overbake, the cakes will continue to cook after being removed from the oven.
Cool in pans for 10 minutes, then turn out onto a wire rack and allow to cool completely. At this point, the brownie cake layers can be stored in the fridge, wrapped tightly in plastic wrap, for up to 2 days before assembling.

Notes

Type of Peanut Butter: For best frosting texture, use creamy commercial peanut butter like Jif or Skippy. Natural peanut butter may separate and affect the consistency.
Make Ahead: You can bake the cake a day in advance and store it tightly wrapped at room temperature. Frosting can be made ahead and stored in the fridge—bring to room temp before spreading.
Storage: Store leftovers in an airtight container at room temperature for up to 3 days, or in the fridge for up to 5 days.
Freezing Instructions: Freeze whole or sliced, tightly wrapped, for up to 2 months. Thaw in the refrigerator overnight and bring to room temperature before serving.
Optional Add-ins: Mix chocolate chips, espresso powder, or swirl in caramel for a twist.
Dietary Swaps: For gluten-free, use a 1:1 gluten-free flour blend. For dairy-free, sub plant-based butter and milk in both the cake and frosting.
Serving Idea: Warm slices slightly and top with a scoop of vanilla ice cream or a drizzle of melted chocolate for an extra decadent touch.