Peanut Butter Sheet Cake with Peanut Butter Frosting

Peanut butter lovers, rejoice! This Peanut Butter Sheet Cake with Peanut Butter Frosting recipe is a dream come true for anyone with a penchant for that rich, creamy, nutty flavor paired with the soft, fluffy texture of cake. The first time I baked this delightful treat, it was for a family gathering, and it disappeared faster than I could have imagined. The combination of a simple yellow cake mix enhanced with peanut butter and topped with a luscious peanut butter frosting makes this cake not only incredibly easy to prepare but also irresistibly delicious. It’s the perfect dessert for parties, potlucks, or any day when you need a little bit of peanut butter goodness in your life.


For the Cake:

  • 1 box yellow cake mix
  • 4 eggs
  • 1/2 cup softened butter
  • 1 cup water
  • 1/2 cup creamy peanut butter

For the Frosting:

  • 3 cups confectioners’ sugar
  • 1/2 cup creamy peanut butter
  • 1/2 cup softened butter
  • 2+ tablespoons milk
  • 1 teaspoon pure vanilla extract
  • A pinch of salt (optional)


Preparing the Cake:

  1. Preheat the Oven: Start by preheating your oven to 325°F (163°C). This ensures your cake cooks evenly.
  2. Prepare the Baking Pan: Lightly grease a 9×13 inch baking pan and set it aside. This helps the cake release easily after baking.
  3. Mix the Batter: Using an electric mixer, cream together the butter and peanut butter until well incorporated. Add the eggs, cake mix, and water, then beat on medium speed for two minutes. The batter should be smooth and well mixed.
  4. Bake: Pour the batter into the prepared baking dish. Bake in the preheated oven for 40 minutes, or until a toothpick inserted into the center of the cake comes out clean.
  5. Cool: Allow the cake to cool completely in the pan before frosting. This ensures the frosting spreads easily and doesn’t melt.

Preparing the Frosting:

  1. Cream the Base: In a mixing bowl, cream together the butter and peanut butter until smooth.
  2. Add the Sugar and Flavors: Gradually add the confectioners’ sugar, vanilla extract, and a pinch of salt (if using). Mix until combined.
  3. Adjust Consistency: Add 2 tablespoons of milk to begin with, then continue to mix. If the frosting is too thick, add more milk, one tablespoon at a time, until it reaches a fluffy, spreadable consistency.

Finishing Touches:

  1. Frost the Cake: Once the cake is completely cooled, spread the frosting evenly over the top. Use a spatula or knife to create swirls or patterns if desired.
  2. Serve and Enjoy: Slice the cake into squares or rectangles and serve. This cake is best enjoyed the day it’s made but can be stored in an airtight container at room temperature for up to 2 days.

Preparation Time

  • Preparation Time: 20 minutes
  • Cooking Time: 40 minutes
  • Total Time: Approximately 1 hour (plus cooling)

Additional Tips

  1. Peanut Butter Selection: Use creamy peanut butter for both the cake and frosting for a smooth texture. Crunchy peanut butter can be used in the cake batter for added texture if desired.
  2. Cake Mix Options: While yellow cake mix is recommended, feel free to experiment with white or chocolate cake mix for different flavors.
  3. Serving Suggestion: For an extra touch of elegance, garnish the frosted cake with chopped peanuts or a drizzle of melted chocolate.
  4. Storing the Cake: If storing longer than 2 days, refrigerate covered to maintain freshness. Let it come to room temperature before serving for the best flavor and texture.
  5. Dairy-Free Adaptation: Substitute the butter with a dairy-free alternative and use a dairy-free milk alternative in the frosting to cater to dietary restrictions.

FAQ Section

Q: Can I make this cake gluten-free? A: Yes, simply use a gluten-free yellow cake mix to make this recipe suitable for those with gluten sensitivities.

Q: How can I make the frosting without an electric mixer? A: You can cream the butter and peanut butter together with a sturdy whisk or a wooden spoon, though it will require more effort. Make sure your butter is very soft to ease the process.

Q: Can I freeze this cake? A: Yes, the cake freezes well even when frosted. Wrap it securely in plastic wrap and freeze for up to 3 months. Thaw in the refrigerator overnight before serving.

Q: Can I add chocolate chips to the cake? A: Absolutely! Fold in 1/2 to 1 cup of chocolate chips into the batter before baking for a delightful peanut butter and chocolate combination.

Q: What can I do if my frosting is too runny? A: If the frosting is too runny, add more confectioners’ sugar, a tablespoon at a time, until the desired consistency is reached.

This Peanut Butter Sheet Cake with Peanut Butter Frosting is a straightforward and delightful treat that’s sure to satisfy any peanut butter craving. Its ease of preparation makes it an ideal choice for both novice and experienced bakers alike. Whether you’re celebrating a special occasion or simply indulging in a bit of baking therapy, this cake promises to deliver comfort, flavor, and a bit of sweetness to your day.