Peanut Butter Chocolate Swirl Cake with Peanut Butter Filling

This is the ultimate cake for peanut butter and chocolate lovers! This moist peanut butter cake is swirled with chocolate cake batter, filled with fluffy peanut butter filling, and frosted with the most beautiful Silky Smooth Chocolate Frosting. Drizzle extra peanut butter and top with peanuts for the perfect fudgey, delicious, classic combination.

This recipe SCREAMS decadence and is one of my all-time favorite cakes. There is no better combination than the classic chocolate and peanut butter twist. This fudgy cake has three rich chocolate cake swirled layers, with smooth, fluffy peanut butter icing between each layer.

I topped it off with a beautiful glossy chocolate ganache frosting. I added extra melted natural peanut butter drizzles and peanuts, but you can top it with whatever your chocolate peanut butter lovers heart desires!

Why This is the Perfect Cake

• Ultimate Flavor Combination for that Sweet Tooth! This cake elevates the timeless pairing of chocolate and peanut butter, creating rich, decadent cake slices.
• Beautiful Presentation:  The stunning swirl of chocolate and peanut butter batters creates a visually impressive cake that is perfect for special occasions.
• Perfect Texture: Moist and tender cake layers paired with fluffy peanut butter filling and smooth, glossy chocolate frosting make for a delightful combination in every bite.
• Versatile Toppings: Customize your cake with drizzles of melted chocolate, peanut butter, or even a sprinkle of chopped peanuts to add a personal touch.
• Crowd Pleaser: This decadent cake with the creamiest peanut butter frosting will impress your guests and become a favorite at any gathering. Whether for birthdays, holidays, or just because, this cake is a showstopper for any special occasion. You will want to make this cake every single time!

WHAT YOU NEED 

Equipment Needed

• Three 8-inch or 9-inch cake pans
• Parchment paper (optional)
• Mixing bowls
• Whisk
• Sifter
• Stand mixer or hand mixer
• Digital Scale (find these in the baking aisle of your local grocery store or online at Amazon)
• Microwave-safe bowl
• Rubber spatula
• Skewer or knife for swirling
• Wire rack for cooling
• Cake stand or serving plate

Shopping List

For the Peanut Butter Cake Batter

Light brown sugar: Adds sweetness and moisture to the cake, while also imparting a rich, caramel-like flavor.
Salted butter: Provides fat for tenderness and richness, with the added salt enhancing the overall flavor.
Creamy peanut butter: The star ingredient, giving the cake its distinct peanut butter flavor and creamy texture.
Large eggs: Act as a binder to hold the cake together, adding structure and moisture.
Vanilla extract: Enhances the overall flavor and aroma, adding depth to the cake.
All-purpose flour: Provides structure to the cake, giving it a tender crumb.
Baking powder: A leavening agent that helps the cake rise, making it light and fluffy.
Baking soda: Works with the baking powder to leaven the cake, providing an additional rise.
Kosher salt: Balances the sweetness and enhances the flavors of all the ingredients.
Whole milk: Adds moisture and richness, contributing to the cake’s tender crumb.

For the Chocolate Cake Batter

Light brown sugar: Adds sweetness, moisture, and a hint of molasses flavor, complementing the cocoa.
Vegetable oil/ Avocado Oil: Provides moisture and a tender texture, keeping the cake soft.
Large eggs: Bind the ingredients together, adding structure and moisture to the cake.
Sour cream: Adds moisture and tanginess, enhancing the cake’s tenderness and flavor.
Vanilla extract: Enhances the overall flavor and complements the chocolate.
All-purpose flour: Provides structure, creating a stable and tender cake crumb.
Dutch process cocoa powder: Gives the cake a rich, deep chocolate flavor and dark color.
Baking powder: Leavens the cake, helping it rise and become light and airy.
Baking soda: Works with the baking powder to provide lift and help the cake rise.
Kosher salt: Balances the sweetness and enhances the chocolate flavor.
Whole milk: Adds moisture, ensuring a soft and tender cake texture.

For The Fluffy Peanut Butter Cake Filling:

• 256 grams (1 cup) creamy peanut butter
• 113 grams (1/2 cup) unsalted butter, softened
• 240 grams (2 cups) confectioners’ sugar
• 4 grams (1 teaspoon) vanilla extract
• 60 ml (1/4 cup) heavy whipping cream (optional)

How to Make a Perfect Swirled Chocolate Peanut Butter Cake

This recipe has two major components: a simple chocolate cake batter and a peanut butter cake batter. The ratio here really matters.

The peanut butter cake batter is the vessel, and the chocolate cake batter is the swirl into the peanut butter cake batter. We are making two batters and then combining them.

You’ll start by making the peanut butter cake batter and dividing that into three pans, reserving about ½ cup of batter.

Next, make the chocolate batter and spoon it in globs over the peanut butter, adding one last dollop of the peanut butter cake batter on top.

Then, gently swirl them together in prepared cake pans, being super careful not to overmix them. You really want to be able to taste both flavor profiles.

Instructions

Prepare the Cake Pans

• Preheat your oven to 350°F (180°C).
• Grease and flour three 8-inch or 9-inch round cake pans or line them with parchment paper.

Make the Peanut Butter Cake Batter

• In a large bowl, stir together 220 g brown sugar, 150 g melted butter, and 128 g peanut butter until combined and creamy.
• Add 3 eggs and 6 g vanilla extract, stirring just until combined. This will be your wet ingredients. 
• In a medium bowl, sift together the dry ingredients 281 g flour, 15 g baking powder, 5 g baking soda, and 3 g kosher salt. This will be your dry ingredients.
• Gradually add the flour mixture to the sugar mixture alternately with 360g milk, beginning and ending with the flour mixture. Mix at low speed and stir until combined.

Make the Chocolate Cake Batter

• In a large bowl, whisk together 310g brown sugar, 112 g of vegetable oil, and 2 eggs until smooth.
• Add 180 g of sour cream and vanilla extract, and mix until combined.
• Sift together 188 g flour, 40 g cocoa powder, 3 g baking powder, 3 g baking soda, and salt. Gradually add the dry ingredients to the wet mixture, mixing until just combined.
• Heat 120g  milk in the microwave for 45 seconds, then add to the batter and mix on medium speed until smooth.

Swirl the Batters Together

• Be sure all 3 layer 8” pans are prepared with parchment paper or sprayed with baking spray.
• Start with the peanut butter batter- divide the peanut butter batter evenly among the three prepared pans. Reserving ½ cup of batter (it is important that you start with the peanut butter cake batter)
• Then divide the chocolate batter on top of the peanut butter batter
• Divide the remaining peanut butter batter over the top of the chocolate.
• Use a knife or skewer to swirl the batters together in each pan, creating a marbled effect. Be careful not to overmix. One or two swirls is enough.

Bake the Cakes

• Bake in the preheated oven for 30-35 minutes or until a toothpick inserted into the center of the cakes comes out clean. Start checking on them about 25-30 minutes and keep an eye on them. 
• Let the cakes cool in the pans for about 10 minutes before transferring them to a wire rack to cool completely.
• Wrap each cake layer in plastic wrap to lock in moisture. Allow the cakes to cool on the counter before fully assembling them. ‘
• If you are not assembling the day of baking you can store them in an airtight container or in a large zip-lock bag and refrigerate for up to 5 days.

Make the Creamy Peanut Butter Frosting

• In a large bowl of an electric mixer or stand mixer fitted with the paddle attachment, beat 256 g peanut butter and 113 g softened room temperature butter until creamy.
• Gradually add 240 g of confectioners’ sugar, beating until smooth.
• Add 4 g vanilla extract and 60 ml heavy whipping cream, beating on medium-high speed until fluffy and well combined.
• Set aside the peanut butter buttercream covered on the counter until you are ready to assemble the cake

Make the silky smooth chocolate Frosting

• Find the complete recipe for this chocolate frosting here!

Assemble the cake

• Place one cooled cake layer on a serving plate or cake stand.
• Spread half of your peanut butter filling in a thin layer in the middle of your cake layer.
• Add the second cake layer and repeat the filling process with the second half of the filling.
• Top with the third cake layer and frost the top and sides with half of the chocolate frosting for the crumb coat. FIND the recipe HERE Chill the cake in the freezer or fridge for 30 minutes.
• Once the cake has chilled, smooth out the entire cake with a warm offset spatula and add the second half of your frosting to the cake. the warm offset spatula will help eliminate any air bubbles.
• Gently swirl in designs into the frosting.

Tasty Toppings

• Simple ingredients are the best toppers! Try adding a few chocolate chips or a drizzle of melted peanut butter. To achieve the perfect melty peanut butter, add a couple of tablespoons to a microwave-safe bowl and microwave it for 10-15 seconds on medium heat until fully melted.
• Any remaining frosting could easily be used to create swirls on top of the cake with a piping bag and star tip.
• Reese’s peanut butter cups would be a perfect candy topping to add to this cake. Enhancing the fluffy peanut butter frosting and moist chocolate cake swirls.

Enjoy your delicious peanut butter chocolate cake with the whole family!

Looking for other decadent treats to make at home?

Red Velvet Cupcakes: These cupcakes are all about that addictive cakey tenderness and the perfect pairing with my zingy cream cheese frosting. The incredibly soft texture and fluffy frosting will make you add these to your go-to recipes!
Pumpkin Chai Caramel Cake: Pumpkin Chai Caramel Cake is perfect for the pumpkin lover. It has three moist Pumpkin cake layers filled with fluffy cream cheese and Ermine frosting. Top this show-stopping cake with a luscious homemade caramel drip and buttercream swirls. 
Toasted Coconut Caramel Latte: This adorable latte brings a big burst of salted caramel flavor and a satisfying crunch from the toasted coconut shreds. The best part? You can whip it up right at home – it’s creamy and delicious, with a hint of salty to balance out the sweetness. 
QUICK RISE -Vanilla Bean Coconut Cream Doughnuts:These doughnuts are so soft and pillowy and burst with creamy coconut vanilla flavor.