Easy Chocolate Cake with Peanut Butter Frosting

This chocolate cake with peanut butter frosting is super easy because it starts with a cake mix to make the moist chocolate cake layer, then it’s covered in a rich and creamy peanut butter frosting.

This cake comes together quickly because the chocolate cake recipe is actually cake-mix-based. It bakes up moist and perfect every time and because you’re adding a few extra ingredients to it, it tastes homemade, just like you made it from scratch.

This chocolate peanut butter cake is the perfect flavor combination and it’ll fast become a favorite. The whole family will love this cake and you won’t mind baking it for them because it’s so quick to throw together. The cake layer is a doctored cake mix, but the frosting is from scratch, so the cake really does taste like it’s a scratch cake.

Another reason it’s so convenient and quick is that it’s baked in a 9×13 inch pan, so the best thing about that is that you don’t have to worry about pulling cake layers out of pans or getting fancy with the decorating. It’s great for special occasions and it’s really great as a bake-and-take dessert for potlucks too.

Top view of chocolate cake with frosting and text overlay.

Hey there! Before you scroll, there are lots of helpful things in this post…including an FAQ section, which may answer any questions you might have about this recipe. Enjoy!

Table of Contents:

Ingredient Notes:

Let’s talk about just some of the ingredients in this recipe. The full list of ingredients will be in the recipe card below. Also, check out the FAQ section to see other tips and ingredient questions.

Chocolate cake mix: This recipe starts off with a cake mix, to make things easy. You’ll doctor it up though, so it’ll end up tasting homemade. You can use any chocolate cake mix you like, but I think Betty Crocker or Duncan Hines works the best.

Instant chocolate pudding mix: This will amp up the chocolate flavor and make it super moist. You’ll just add this in dry, but make sure it’s the ‘instant’ pudding mix and not the ‘cooked’ type.

Sour cream: This is always the star in cake recipes. It adds a little flavor and a lot of moisture. This is one of the ingredients that will make this cake taste like it’s from scratch.

Vanilla extract: It’s always nice to add just a touch of vanilla to cake batter, even if it’s a chocolate cake. It just adds a nice dimension to the cake and helps it get the ‘from scratch’ taste.

Unsalted butter: The peanut butter frosting calls for unsalted butter. It’s best to use real butter and not margarine here because nothing beats the taste of real butter in frosting. It’s also best to try and use unsalted butter, instead of salted butter, as the peanut butter will already have a good amount of salt in it already.

Peanut butter: You can’t get peanut butter buttercream without peanut butter, right? I prefer to use creamy peanut butter, but you could always go with crunchy if that’s what you like.

Confectioner’s sugar: You’ll use this for the frosting as it will thicken it up and add sweetness.

Top view of cake with peanut butter icing in a rectangle pan.

How to Make this Cake:

Here’s how to prepare this cake. The full instructions will be in the recipe card below.

Step 1:

First, you’ll need to make the cake. For that, make sure to preheat the oven to 350 degrees F and grease or spray a 9×13 inch pan very well.

Step 2:

Now add all of the cake ingredients to a large bowl and mix well with an electric mixer on medium to medium-high speed for about two minutes. Note that the batter will be thick.

Step 3:

Spread the cake batter evenly into the sprayed pan and bake for approximately 35-40 minutes. The cake is done baking when a toothpick inserted into the center comes out with a few moist crumbs on it or clean, but no raw batter.

Step 4:

Once the cake is fully baked, set it on a wire rack to cool completely before adding the buttercream.

Steps 1 through 4 of cake process.

Step 5:

Now it’s time to make the frosting. You’ll mix the butter, peanut butter and vanilla extract well with an electric mixer on medium to medium-high until very smooth.

Step 6:

Next, add the confectioner’s sugar, vanilla extract and 3 tablespoons of milk and mix on low until incorporated, then on medium until well mixed.
Then, check the consistency and if it’s too thick, add another tablespoon of milk. If it’s too thin, just add another 1/2 cup of confectioner’s sugar and mix well. Once you reach the desired consistency, mix it on medium-high speed for about a minute, so that the icing becomes super fluffy.

Step 7:

Make sure that the cake has cooled completely, then add the frosting.

Step 8:

Serve at room temperature. You can also add chopped peanut butter cups, crushed Oreos or chocolate chips on top.

Steps 5 through 8 of cake process collage.

Tips & FAQs:

What type of chocolate cake mix should I use?

Just make sure to use a cake mix that’s around 15 oz. Any chocolate cake mix will probably do, but I prefer Betty Crocker or Duncan Hines.

Do I need to add the ingredients that are on the back of the cake mix box?

No, don’t add the ingredients that are listed on the back of the cake mix box. Just add the cake mix dry to the bowl.

Do I use instant pudding or the cooked pudding mix?

Use the instant pudding mix.

Should I prepare the pudding per the directions on the pudding mix box?

No, just add the pudding mix in dry.

I don’t have sour cream or can’t get it. Can I substitute it?

Yes, you can substitute it with plain yogurt.

I don’t have unsalted butter. Can I use salted butter for the frosting?

It’s really best to use unsalted butter for the frosting because the peanut butter already has a good amount of salt added and using salted butter, will just add more. If you cannot get unsalted butter, then just use what you have.

What type of peanut butter should I use?

You can use any brand you like. I prefer Jif or Peter Pan creamy, but use what you like.

Do I need to sift the confectioner’s sugar?

No, not unless it has large lumps in it.

Is there an easier option for the frosting?

Yes! You could use canned vanilla frosting and add in peanut butter until you get just the right amount.

How can I tell when this cake is done baking?

The cake is done baking when a toothpick inserted into the center comes out with a few moist crumbs or clean, but no raw batter.

Can this cake be made into a layer cake?

Yes, absolutely. Just add the cake batter to two, well-greased 8 inch round cake pans and bake.

How do I store this cake and how long does it last?

This cake can be stored, well covered, at room temperature for approximately 3 days, then stored in the refrigerator for another 2-3 days to prolong freshness. This cake can last up to 6 days when stored properly.

How should I serve this cake?

This cake is best served at room temperature. If cold, allow it to come to room temperature before serving. or pop a slice in the microwave and warm for about 10 seconds.

What can be added to this cake?

You can add chocolate chips to the cake batter if desired. After the cake is baked, cooled and frosted, you could add crushed Oreos, chopped peanut butter cups, or sprinkle chocolate chips over it.

Close up view of moist chocolate cake with frosting on a plate with a fork.

Supplies used for this recipe:

This post contains affiliate links. As an Amazon Associate, I earn from qualifying purchases. 

Video:

Chocolate cake slice with peanut butter frosting on a white plate.

Easy Chocolate Cake with Peanut Butter Frosting

This chocolate cake with peanut butter frosting is super easy because it starts with a cake mix to make the moist chocolate cake layer, then it’s covered in a rich and creamy peanut butter frosting.
No ratings yet
Print Pin Save Rate
Course: Dessert
Cuisine: American
Keyword: chocolate cake, peanut butter frosting
Prep Time: 20 minutes
Cook Time: 35 minutes
Total Time: 55 minutes
Servings: 15 slices
Calories: 458kcal
Author: Kara @ Quick and Easy Baking

Ingredients

For the cake:

  • 1 15.24 ounce box chocolate cake mix (I used Betty Crocker's chocolate fudge cake)
  • 1 3.9 ounce box Jello instant chocolate pudding mix
  • 1 cup sour cream
  • 1/2 cup canola oil
  • 1/2 cup milk
  • 4 large eggs
  • 1 teaspoon vanilla extract

For the frosting: (See easier frosting option in notes.)

  • 1 cup unsalted butter, room temperature (2 sticks)
  • 1 cup peanut butter
  • 4 cups confectioner’s sugar
  • 2 teaspoons vanilla extract
  • 3-4 tablespoons milk

Instructions

For the cake:

  • Preheat oven to 350 degrees F. Grease or spray a 9 x 13 inch pan very well.
  • In a large bowl, mix all the cake ingredients on medium to medium-high speed for about two minutes. Batter will be thick.
  • Spread the batter evenly into the pan and bake for approximately 35-40 minutes. Cake is done baking when a toothpick inserted into the center comes out with a few moist crumbs or clean, but no raw batter.
  • Once baked, set on a wire rack to cool completely before adding frosting.

For the frosting:

  • Mix the butter, peanut butter and vanilla extract well with an electric mixer on medium to medium-high until very smooth.
  • Add the confectioner’s sugar, vanilla extract and 3 tablespoons of milk and mix on low until incorporated, then on medium until well mixed.
  • Check the consistency. If it’s too thick, add another tablespoon of milk. If it's too thin, add another 1/2 cup of confectioner's sugar and mix well.
  • Once the desired consistency is reached, mix on medium-high speed for about a minute, so the icing becomes fluffy.
  • Add frosting to cooled cake.
  • (See an even easier option for the frosting in the notes.)

Notes

This cake can be stored, well covered, at room temperature for approximately 3 days, then stored in the refrigerator for another 2-3 days to prolong freshness. This cake can last up to 6 days when stored properly.
This cake is best served at room temperature. If cold, allow it to come to room temperature before serving. or pop a slice in the microwave and warm for about 10 seconds.
For an easier frosting: Add peanut butter to canned vanilla frosting and top cake.
Nutritional values are an estimate. Make sure to check out the TIPS & FAQs for this recipe in the blog post, which may answer questions you may have.
*This recipe card may contain affiliate links. As an Amazon Associate, I earn from qualifying purchases.

Nutrition

Calories: 458kcal | Carbohydrates: 37g | Protein: 6g | Fat: 33g | Saturated Fat: 12g | Polyunsaturated Fat: 5g | Monounsaturated Fat: 13g | Trans Fat: 1g | Cholesterol: 87mg | Sodium: 103mg | Potassium: 155mg | Fiber: 1g | Sugar: 34g | Vitamin A: 555IU | Vitamin C: 1mg | Calcium: 48mg | Iron: 1mg

How to Share

I’d love for you to share this recipe link or tag it, but please do not share screenshots or copy/paste the recipe to social media as the content and photographs are copyright protected and we (bloggers) work really hard on our content. Sharing the link, tagging us on socials and pinning it is super appreciated though!

Pin image of chocolate cake and peanut butter buttercream with text.

Leave a Comment

Recipe Rating