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Buttermilk and brown sugar give this peanut butter cake recipe it’s delicious flavor and tender texture. It’s an easy homemade cake in a 9×13″ pan.

Peanut butter has always been favorite flavor in our house. That rich, nutty peanut butter flavor is delicious in cookies, no bake bars and even mousse, but there’s not much better than peanut butter cake.

I’ve made a semi-homemade Nutter Butter cake (perfect for peanut butter lovers) for years, but it was time I shared our family’s favorite peanut butter cake. I found this in an old Mennonite cookbook that I’ve had for years. I topped it with our best chocolate and peanut butter frosting. And let me tell you. This peanut butter sheet cake is unforgettable.

closeup of a piece of peanut butter cake with swirls of frosting on a plate with a fork

About this Peanut Butter Cake Recipe:

Flavor: As the name suggests, the dominant flavor of peanut butter cake is peanut butter! It has a rich, nutty flavor that is both sweet, but not overly so. Chocolate buttercream pairs well with the peanut butter cake.
Texture: This cake is rich and dense. The peanut butter and buttermilk keep it moist. The peanut butter adds a creamy, slightly sticky texture to the cake.
Method: To keep this recipe quick and easy, I baked it in a standard 9×13″ baking pan. You could use 2 8″ round cake pans or make cupcakes if you’d like. Watch the baking time, as both won’t take as long to bake.

What kind of peanut butter is best for cake?

The best type of peanut butter to use is creamy, smooth peanut butter. This type of peanut butter is easy to work with and will evenly distribute throughout the cake batter.

A few popular brands of creamy, smooth peanut butter that are widely available are Jif, Skippy, and Peter Pan. You can also find many store-brand varieties that will work well for baking.

Ingredients for Peanut Butter Cake

Butter. If you don’t have salted butter, add a dash of salt.
Creamy peanut butter. Creamy Jif, Skippy or Peter Pan peanut butter are popular brands for baking. I’ve not yet tested this with natural peanut butter. And crunchy peanut butter would make the cake a little more crumbly.
Brown sugar. Brown sugar adds moisture and a deep flavor to this cake.
Eggs. Room temperature eggs mix in better to cake mix than cold eggs.
Warm water. A little bit of water added into the cake mix helps it be lighter.
Buttermilk. Buttermilk is acidic, which helps break down gluten strands, resulting in a tender cake.
All-purpose flour. Use cake flour if you’d like, but it isn’t necessary for this cake.
Salt. I bake with standard table salt unless otherwise specified.
Baking soda. This is needed to help the cake rise.

an unfrosted peanut butter cake on a table

Tips for Making Peanut Butter Cake

1 Bowl Needed. Some cakes need to be dry ingredients and wet ingredients mixed in separate bowls, but the flour mixture gets mixed in the same bowl as the butter mixture for this cake. Quick and easy.
Use room temperature ingredients. The butter should be room temperature softness and eggs at room temperature as well. The water needs to be warmed to at least room temperature, but not hot.
Scrape the sides of the bowl. It’s always important to scrape the sides of the bowl when you are mixing cookies or cake, especially when mixing with an electric mixer. But this is especially important when using only one bowl to mix.
The cake is done when the center springs back as you touch it. You can also use the timeless toothpick test, but it’s ok if there are a few moist crumbs on the toothpick after you pull it out of the cake. There should not be any batter on it though.
Allow the cake to cool before frosting it. Otherwise the frosting will melt into the cake.
Use real butter for the frosting. Don’t use margarine or shortening. Butter gives you the best flavor and texture.
For a pretty look, make the swirled chocolate and peanut butter frosting, but if you need something quick, make just one type of frosting and spread it over the top of the cooled cake with an offset spatula. If you’re only making one of the frostings, you may want to double it so there is enough frosting for the whole cake.

chocolate frosting and peanut butter frosting in bowls on a table

Recipe Variations

Add 1 cup of mini chocolate chips to the cake batter for a chocolate chip cake.
Love cheesecake? Try a cream cheese frosting and sprinkle with chopped peanuts rather than chocolate frosting.

overhead view of a cake in a pan with swirls of peanut butter and chocolate frosting

Storage Instructions

Room temperature: Store in an airtight container on the counter for up to 24 hours.
Refrigerator: Store this cake in an airtight container in the fridge for up to 5 days. Bring to room temperature before eating.
Freezer: Freeze the cake whole or sliced in an airtight container for up to 2 months. I double wrap by wrapping in plastic wrap, then placing the wrapped pieces in another storage container. Thaw at room temperature before eating.

a piece of peanut butter cake sitting on a plate

a piece of frosted peanut butter cake on a glass plate

Peanut Butter Cake Recipe

4.67 from 21 votes

Buttermilk and brown sugar give this peanut butter cake recipe it's delicious flavor and tender texture. It's an easy homemade cake in a 9×13" pan.

Servings 15

Prep Time 30

Cook Time 28

Total Time 58

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Ingredients

For the peanut butter cake:

¼ cup butter salted, softened, 2 ounces
¼ cup creamy peanut butter 63 grams
1 ½ cups brown sugar 300 grams
2 large eggs room temperature
½ cup water warmed, 4 ounces
1 cup buttermilk 8 ounces
2 cups all-purpose flour 260 grams
1 teaspoon salt 7 grams
1 teaspoon baking soda 6 grams

For the Peanut Butter Frosting:

1/2 cup salted butter room temperature, 4 ounces
1 cup creamy peanut butter* 250 grams
2 cups powdered sugar 260 grams
3 tablespoons heavy cream or whole milk

For the Chocolate Buttercream:

1/2 cup salted butter room temperature, 4 ounces
1/4 teaspoon salt
1 teaspoon vanilla extract
1 3/4 cups powdered sugar 228 grams
1/4 cup unsweetened cocoa powder 25 grams
2 tablespoons heavy cream

Instructions

Make the peanut butter cake:

Preheat the oven to 350ºF. Spray a 9×13” baking dish with cooking spray.
In a large mixing bowl, use an electric hand mixer to mix the butter, peanut butter and brown sugar until smooth. Scrape the sides of the bowl.
Add in the eggs, warm water and buttermilk. Mix well until evenly combined, scraping the sides of the bowl as needed.
Add the flour, salt and baking soda. Mix just until combined.
Pour the batter into the prepared pan.
Bake for 25-28 minutes. The cake is done when a toothpick inserted into the center of the cake comes out clean or with a few moist crumbs.
Allow the cake to cool on a wire rack.

Make the peanut butter frosting:

In the bowl of a stand mixer, cream together butter and peanut butter for 2 minutes.
Add 1 cup of powdered sugar and mix until blended.
Add 2 tablespoons of heavy cream and beat until completely blended.
Add in the remaining cup of powdered sugar. Beat for 1 minute.
Test the frosting and if you need another tablespoon or two of heavy cream to make the frosting spreadable, add it in.

Make the chocolate buttercream:

In a stand mixer with the beater blade, beat the butter for 1-2 minutes until it is smooth, creamy and nearly white in appearance.
Add in the salt and vanilla. Mix until incorporated.
With the mixer on low speed, slowly add in the powdered sugar and cocoa powder.
Add the heavy cream, a tablespoon at a time, mixing slowly until it is the consistency that you’d like.
Beat for 1 minute on medium speed until smooth and creamy.

Assemble the cake:

Place a large Wilton tip in a piping bag (Wilton 1M or 2D). Place a big scoop of peanut butter frosting into the piping bag, pressing it down towards the tip, but keeping the frosting on just half of the bag.
Place a big scoop of the chocolate frosting into the other side of the piping bag, pressing it down towards the tip as well. The bag should have chocolate on one side and peanut butter on the other.
Squeeze the frosting down to the tip, then pipe swirls all over the top of the cake. Pipe stars around the flowers if there are spaces of plain cake showing.
Cover the cake and store at room temperature for up to 24 hours. Then refrigerate or freeze any leftovers.

Notes

*Skippy or Jif are our preferred brands of peanut butter.

*Line the baking pan with parchment paper if you’d like to remove it from the pan easily.

*You can choose just one frosting and spread it all over the top if you’d like rather than piping swirls.

Refer to the article above for more tips and tricks.

The calories shown are based on the cake being cut into 15 pieces, with 1 serving being 1 slice of cake. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate. **We are not dietitians and recommend you seek a nutritionist for exact nutritional information. The information in the nutrition box are calculated through a program and there is room for error. If you need an accurate count, I recommend running the ingredients through your favorite nutrition calculator.**