Peanut Butter Sheet Cake is a moist sheet cake topped with a super creamy and sweet peanut butter icing. It is a peanut butter lover’s dream and perfect for potlucks and picnics.

Slice of Peanut Butter Sheet Cake getting lifted out of pan.

Peanut butter is practically the only food I can eat every single day and not get tired of. I often start my day with a banana and a spoon full of peanut butter. I absolutely love the stuff.

Normally when it comes to desserts, I prefer peanut butter paired with chocolate. AKA the best thing ever.

But sometimes a pure peanut butter dessert is just what I’m craving.

Peanut Butter Sheet Cake with a fluffy peanut butter frosting. Love this for potlucks!

With peanut butter in the cake batter and the icing, there’s plenty of peanut butter flavor in this peanut butter sheet cake. It’s like the peanut butter version of a Texas Sheet Cake.

Super Moist Cake Batter

Too often peanut butter cake is dry in texture. This one is super moist. Be sure to measure the flour correctly and use a shelf-stable creamy peanut butter such as Jif or Skippy.

Light and Fluffy Peanut Butter Frosting

The frosting is what makes this dessert truly amazing. The addition of two tablespoons of instant vanilla pudding mixture creates a wonderful texture in the frosting and helps stabilize it.

How To Serve

It’s baked in a 10×15-inch pan and can easily be cut into 20 pieces so it is perfect for bringing to a summer potluck or picnic. If you want to dress it up a little, cut it into squares and then place a mini peanut butter cup on top of each one.

Peanut Butter Sheet Cake with a fluffy peanut butter frosting. Love this for potlucks!

Recipe Tips

  • I use salted butter for this recipe. If you use unsalted, you may want to increase the amount of salt added to half a teaspoon.
  • If you don’t have buttermilk you can make a substitute for buttermilk by adding half a tablespoon of lemon juice or vinegar to a liquid measuring cup. Then add milk to the half cup mark. Stir and let sit for 5 minutes.

How To Store Peanut Butter Sheet Cake

This cake can be stored at room temperature for 4 days. It can also be frozen for up to 3 months.

Peanut Butter Sheet Cake with a fluffy peanut butter frosting.

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More Peanut Butter Desserts


Peanut Butter Sheet Cake

4.94 from 33 votes

By Christin Mahrlig

Prep: 20 minutes
Cook: 22 minutes
Total: 42 minutes
Servings: 20 servings
Peanut Butter Sheet Cake is a moist sheet cake topped with a super creamy and sweet peanut butter icing. Perfect for potlucks!

Equipment

  • 10×15-inch sheet pan
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Ingredients

Cake

  • 2 cups all-purpose flour
  • 2 cups sugar
  • 1/2 teaspoon baking soda
  • 1/4 teaspoon salt
  • 1 1/2 (12 tablespoons) sticks butter
  • 1 cup water
  • 1/2 cup peanut butter
  • 1/4 cup vegetable oil
  • 2 eggs
  • 1/2 cup buttermilk
  • 1 teaspoon vanilla extract

Frosting

  • 2 sticks (1 cup) butter,, softened
  • 3/4 cup peanut butter
  • 3 cups confectioners’ sugar
  • 3 to 4 tablespoons milk
  • 2 tablespoons instant vanilla pudding mix

Instructions 

  • Preheat oven to 350 degrees. Grease a 10x15x1 inch jellyroll pan.
  • In a large bowl, whisk together flour, sugar, baking soda, and salt.
  • Combine 1 1/2 sticks butter and 1 cup water in a medium saucepan and bring to a simmer. Sitr to make sure all butter is melted.
  • Whisk 1/2 cup peanut butter and vegetable oil into butter mixture. Stir into flour mixture.
  • Whisk together eggs, buttermilk, and vanilla extract. Stir into flour mixture until well combined.
  • Pour batter into prepared pan.
  • Bake for 22 to 26 minutes or until a toothpick inserted in middle comes out clean. Let cool.
  • To make frosting, use an electric mixer to beat butter and peanut butter together until smooth.
  • Add half of confectioners’ sugar and half of milk and beat until smooth.
  • Add remaining confectioners’ sugar, milk and the vanilla pudding mix and beat until smooth. Add a little more milk if necessary.
  • Spread frosting on cake.

Video

Nutrition

Calories: 469kcal | Carbohydrates: 53g | Protein: 6g | Fat: 27g | Saturated Fat: 9g | Polyunsaturated Fat: 6g | Monounsaturated Fat: 10g | Trans Fat: 2g | Cholesterol: 42mg | Sodium: 275mg | Potassium: 127mg | Fiber: 1g | Sugar: 41g | Vitamin A: 321IU | Calcium: 26mg | Iron: 1mg

Nutrition information is automatically calculated, so should only be used as an approximation.

Did you make this?Leave a comment below and tag us @spicysouthernkitchen on social media!

Originally posted July 14, 2016.

More Potluck Desserts

This Butterfinger Chocolate Lush has an oreo cookie crumb crust, a peanut butter layer with crushed butterfingers, a chocolate pudding layer, and Cool Whip on top.

Butterfinger Lush

Pineapple Sheet Cake

Pineapple Sheet Cake

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Recipe Rating




84 Comments

  1. Laura Crawford says:

    Can you also use this recipe in a regular round cake pan for a dbl layered cake? Thx.

    1. Christin Mahrlig says:

      Yes, but the baking time will need to be less.

  2. DiAnne says:

    What brand of peanut butter do you use; also is it natural peanut butter or the regular kind?

    1. Christin Mahrlig says:

      I use Jif peanut butter. The regular kind.

  3. The Better Baker says:

    OH MY! Crazy over this..AND THAT FROSTING! I am a regular eater of pb & banana too! ?

  4. Amy says:

    A great aunt of mine used to make something like this and I have been searching for YEARS to find anything remotely like it! So excited to give this a try!

  5. Maritza says:

    Hi! I really love peanut butter so I want to try this recipe. The only problem I have here in Puerto Rico is that I can’t find buttermilk anywhere. Can I use regulR milk? Appreciate your response. ?

    1. Karen says:

      A reliable substitute for buttermilk is to combine whole milk with vinegar. In this recipe, mix about 1/2 teaspoon vinegar with the 1/2 cup milk.

  6. Mary // chattavore says:

    Christin!!!! This sounds amazing. Dessert + salt = YUM. Can’t wait to try it.

  7. Jessica @ A Kitchen Addiction says:

    Love that thick layer of peanut butter frosting!

  8. Monica says:

    Oh yum! My son and I are actually going to bake a chocolate sheet cake together this afternoon. This might be even better! Hope you are enjoying the summer.

  9. Gayle @ Pumpkin 'N Spice says:

    Mmm I’ve never had a pb sheet cake before! This looks fantastic, Christin! I could just dig into that frosting with a spoon…yum!

  10. Alaina @ A Not So Quiet Kitchen says:

    Yum! This looks so delicious! I just love peanut butter frosting!

    1. Sharmilia Rice says:

      The cake really was delicious. But my question is how should the cake be stored? How long will it stay moist out on the counter under a lid or would the fridge be better?