Peanut Butter Cake

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 9x13" pan.

Prep Time30

Cook Time28

Total Time58

Course: Dessert

Cuisine: American

Keyword: 9x13" cake, easy cake recipe, peanut butter cake recipe

Servings:

Calories: 565kcal

Author: Julie Clark

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 9x13” 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. ¼ cup butter, ¼ cup creamy peanut butter, 1 ½ cups brown sugar
Add in the eggs, warm water and buttermilk. Mix well until evenly combined, scraping the sides of the bowl as needed. 2 large eggs, ½ cup water, 1 cup buttermilk
Add the flour, salt and baking soda. Mix just until combined. 2 cups all-purpose flour, 1 teaspoon salt, 1 teaspoon baking soda
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. 1/2 cup salted butter, 1 cup creamy peanut butter*,
Add 1 cup of powdered sugar and mix until blended. 2 cups powdered sugar
Add 2 tablespoons of heavy cream and beat until completely blended. 3 tablespoons heavy cream
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. 1/2 cup salted butter
Add in the salt and vanilla. Mix until incorporated. 1/4 teaspoon salt, 1 teaspoon vanilla extract
With the mixer on low speed, slowly add in the powdered sugar and cocoa powder. 1 3/4 cups powdered sugar, 1/4 cup unsweetened cocoa powder
Add the heavy cream, a tablespoon at a time, mixing slowly until it is the consistency that you'd like. 2 tablespoons heavy cream
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.**

Nutrition