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Peanut Butter Sheet Cake

Peanut Butter Sheet Cake is a new take on a classic Texas Sheet Cake. The soft and fluffy peanut butter cake is topped with a delicious, rich peanut butter icing. It’s just the right ratio of cake to icing to make this a perfect Peanut Butter Sheet Cake.

Go big or go home.

That statement certainly applies when you talk about the flavor in this Peanut Butter Sheet Cake.

We’ve got peanut butter in the cake, peanut butter in the icing, and peanuts on top.

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Key to Success #1 – Let’s Talk Pans

As with any good sheet cake, you want your cake to be thin so that you can get the proper cake to icing ratio – meaning, MORE ICING!

This cake is best cooked in a jellyroll pan, which is typically 12X17 by 1-inch tall.

Don’t go trying to bake this delicious cake in a 9X13 casserole dish. It won’t be the same!

This recipe for Peanut Butter Sheet Cake will fill up a 12X17 by 1-inch tall pan.

Make sure the pan that you use is comparable in size so that it doesn’t overflow when you try to pour the icing on top.

Peanut Butter Sheet Cake

Key to Success #2 – Frost It While It’s Warm

I can’t say this enough – frost your cake while it’s still warm.

A warm cake allows your rich frosting to melt into the cake and make it even more delicious.

You can pour the icing over the cake as soon as it comes out of the oven.

The icing is thin enough that it’s pourable so I just drizzle it all over the warm cake then spread it to fully cover using the back of a spoon or a spatula.

It’s just enough to cover the cake without spilling over the lip of the pan.

Peanut Butter Icin

This is not a great picture but I just wanted to show how the icing drizzles over the cake so I just have to spread it a bit with a spoon.

If you like peanuts, you can chop up some roasted peanuts and sprinkle them over your cake while the icing is still warm.

I think it really makes a pretty presentation, but it’s optional.

I have some in my house who are not fans of peanuts so I just had peanuts that we could sprinkle over our piece of cake if we wanted them. YUM!

Peanut Butter Sheet Cake with Peanut Butter Icing

A Peanut Butter Sheet Cake is great to take to a family dinner or a potluck.

It makes a huge cake and it’s easy to cut and serve.

You don’t have to worry about how to cut a round layered cake with this one!

Save this Peanut Butter Sheet Cake recipe to your favorite Peanut Butter Lovers board or your Easy Cakes board.

Peanut Butter Sheet Cake
Peanut Butter Sheet Cake Topped with Peanuts

Peanut Butter Sheet Cake

This Peanut Butter Sheet Cake has the perfect ratio of icing to cake! The peanut butter cake is so soft and fluffy and it’s covered with a rich peanut butter frosting. That makes it a real winner in my book. 
4.50 from 2 votes
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Course: Dessert
Cuisine: American
Prep Time: 10 minutes
Cook Time: 20 minutes
Total Time: 30 minutes
Servings: 20 servings
Calories: 383kcal
Author: Jennifer


For the Cake:

For the Icing:


  • Preheat oven to 375 degrees F.
  • In medium pot, add the peanut butter, water and butter. Bring to a boil then remove from heat.
  • In a separate bowl, mix together sugar, brown sugar, flour, salt, and baking soda. Add to the peanut butter mixture and stir well.
  • Add eggs, buttermilk, and vanilla. Mix well. 
  • Pour into greased 12X17 jellyroll pan or large rimmed baking sheet. Bake for 15-20 minutes until top springs back when lightly touched.
  • While cake is baking, in a small pot bring the butter, buttermilk, and peanut butter to a boil. Remove from heat and stir in powdered sugar and vanilla. Pour icing over the cake as soon as it comes out of the oven.


Top with chopped roasted peanuts, if desired. 


Serving: 1grams | Calories: 383kcal | Carbohydrates: 54g | Protein: 5g | Fat: 17g | Saturated Fat: 4g | Polyunsaturated Fat: 4g | Monounsaturated Fat: 8g | Trans Fat: 0.002g | Cholesterol: 18mg | Sodium: 368mg | Potassium: 111mg | Fiber: 1g | Sugar: 43g | Vitamin A: 549IU | Vitamin C: 0.03mg | Calcium: 35mg | Iron: 1mg
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