This Peanut Butter Sheet Cake takes less than an hour to make from start to finish. It’s topped with a fudgy, candied peanut butter icing that’s out-of-this-world amazing! Recipe includes a how-to video.
A Peanut Butter Lover’s Dream Cake
Sure, layer cakes are impressive, but there’s something to be said about classic, from-scratch sheet cakes. Their ease (no leveling, layering, crumb coating), flavor (just as good!), and nostalgic, homey feel is simply unparalleled in the cake world. Today’s tender peanut butter sheet cake is no different; it’s simple, flavorful, and is decorated and served right in its baking dish. It’s a classic!
This cake has a balanced peanut butter flavor that’s prominent without being too overwhelming. My favorite part is the frosting though…it’s like a candied peanut butter fudge topping! It’s super rich (so we use just the right amount) and pairs beautifully with the texture of the cake.
I think you’re really going to love this one, so let’s dive right in!
What You Need
Here are the key ingredients in this peanut butter sheet cake:
- Peanut butter. Do NOT use “natural” peanut butter that separates! Unfortunately, in many peanut butter recipes (like my buckeyes, peanut butter balls, and the frosting on my peanut butter chocolate cake) readers have reported oily failures when they tried to use natural peanut butter, so best bet is to avoid it here. I prefer to use creamy peanut butter, but crunchy could be used instead.
- Butter. I highly recommend using unsalted butter in this recipe (and most of my others!). I have a post comparing salted vs. unsalted butter that you can check out if you’d like an in-depth explanation, but essentially, unsalted butter allows for better precision. This is especially important when using a salted ingredient like peanut butter
- Buttermilk. If you don’t have buttermilk, you can always use my easy buttermilk substitute, but the real stuff will give you the best flavor and moisture.
- Brown sugar. Light brown sugar adds some depth to the cake that really complements the peanut butter flavor well, like in my peanut butter cookies.
- Baking soda. Make sure to use baking soda and not baking powder–they are not the same thing! If you want to learn more about the differences between the two, read my post on baking powder vs. baking soda.
SAM’S TIP: When making your frosting, you’ll want to stir CONSTANTLY once the butter melts. When the mixture comes to a boil, remove it immediately to prevent any burning.
Remember, this is just an overview of the ingredients I used and why. For the full recipe please scroll down to the bottom of the post!
How to Make It
- Whisk together the dry ingredients and sugars in a large bowl and set aside.
- Bring oil, butter, and water to a boil over medium heat.
- Remove the pan from the heat and stir in your peanut butter until it’s melted and smooth.
- Pour your peanut butter mixture into your dry ingredients and mix until combined. Let cool 5-10 minutes.
- Combine buttermilk, eggs, and vanilla, then stir this into your prepared batter until just combined.
- Pour batter into a greased pan and bake for 30-32 minutes.
- Measure and sift your sugar, then set it aside.
- Cook buttermilk, butter, peanut butter, and salt over medium-low heat until the butter melts, then increase heat to medium and whisk constantly.
- Once the mixture boils, remove it from the heat and whisk in the powdered sugar and vanilla.
- Pour the icing over the warm cake and use an offset spatula to smooth.
SAM’S TIP: Once your frosting is fully prepared, you need to work quickly to get it on the cake. The frosting will solidify somewhat, and you want that to happen on the cake–not in the bowl!
Frequently Asked Questions
Nope! Not unless you want it refrigerated, anyway. Simply store at room temperature covered or in an airtight container and enjoy within three days.
Definitely! When I first published this recipe, I used my peanut butter frosting (with some chocolate added to half the batter for a swirl), so that’s always an option. My Texas sheet cake frosting, my chocolate fudge frosting, or just about any other frosting would work well, too.
Yes! You’ll want to wrap it well and store in an airtight container for up to three months.
Baking, decorating, and serving all in the same pan–the beauty of a sheet cake!
Enjoy!
Let’s bake together! I’ll be walking you through all the steps in my written recipe and video below! If you try this recipe, be sure to tag me on Instagram, and you can also find me on YouTube and Facebook
Peanut Butter Sheet Cake
Ingredients
Sheet Cake
- 2 cups (250 g) all-purpose flour
- 1 cup (200 g) granulated sugar
- ¾ cups (150 g) light brown sugar firmly packed
- ¾ teaspoon baking soda
- ¾ teaspoon salt
- 1 cup (237 ml) water
- ¾ cup (177 g) unsalted butter cut into pieces
- ¼ cup (60 g) canola or vegetable oil
- ½ cup (145 g) creamy peanut butter
- ½ cup (118 ml) buttermilk
- 2 large eggs room temperature preferred
- 1 ½ teaspoons vanilla extract
Fudgy Peanut Butter Frosting
- 4 cups (500 g) powdered sugar
- ½ cup (118 ml) buttermilk
- 10 Tablespoons (150 g) unsalted butter cut into pieces
- ⅔ cup (165 g) creamy peanut butter
- ¼ heaping teaspoon salt
- 1 teaspoon vanilla extract
Recommended Equipment
Instructions
- Preheat oven to 350F (175C) and lightly grease a 13×9 baking pan. Set aside.
- In a large bowl, whisk together flour, sugars, baking soda, and salt.2 cups (250 g) all-purpose flour, 1 cup (200 g) granulated sugar, ¾ cups (150 g) light brown sugar, ¾ teaspoon baking soda, ¾ teaspoon salt
- In a medium-sized saucepan, combine water, butter, and oil. Heat over medium heat, stirring occasionally until butter is melted and bring to a boil.1 cup (237 ml) water, ¾ cup (177 g) unsalted butter, ¼ cup (60 g) canola or vegetable oil
- Once boiling, remove from heat and add peanut butter. Stir until peanut butter is dissolved and mixture is smooth. Add to bowl with dry ingredients and stir until combined. Set aside to cool for 5-10 minutes.½ cup (145 g) creamy peanut butter
- Meanwhile, in a separate bowl, whisk together buttermilk, eggs, and vanilla extract.½ cup (118 ml) buttermilk, 2 large eggs, 1 ½ teaspoons vanilla extract
- Gradually stir buttermilk mixture into batter, stirring until just combined.
- Pour batter evenly into prepared pan and transfer to center rack of 350F (175C) preheated oven and bake for 30-32 minutes or until a toothpick inserted in the center comes out clean or with moist crumbs. Prepare frosting.
Fudgy Peanut Butter Frosting
- Measure out sugar and set aside (if you’re worried about lumps in your icing, sift the sugar after measuring).4 cups (500 g) powdered sugar
- Combine buttermilk, butter, peanut butter, and salt in a medium-sized saucepan. Cook over medium-low heat until butter is melted. Increase heat to medium and bring to a boil while stirring constantly. Once boiling, remove from heat.½ cup (118 ml) buttermilk, 10 Tablespoons (150 g) unsalted butter, ⅔ cup (165 g) creamy peanut butter, ¼ heaping teaspoon salt
- Immediately add powdered sugar and vanilla extract.1 teaspoon vanilla extract
- Whisk until smooth and immediately pour evenly over cake (in the pan, I do not remove my cake from the pan).
Notes
Jelly Roll Pan
To bake in a jellyroll pan (15×10″ pan) bake on 350F for 18-22 minutes.Peanut Butter
I recommend against using a “natural” variety of peanut butter (the kind where the oil separates out) as this could affect the texture of the cake.Creamy or crunchy peanut butter will work here, I prefer creamy for smoother results, but if you opt for crunchy you’ll just have small peanut pieces in your cake and icing.
Storing
Cover the pan with foil or plastic wrap and store at room temperature for up to three days.Nutrition
Nutritional information is based on third-party calculations and should be considered an estimate only. Actual nutritional content will vary based upon brands used, measuring methods, cooking method, portion sizes, and more.
Emma
I haven’t made this yet, but it looks like a nice cake. Do you think this would taste good with a semi-sweet chocolate ganache dripped over the top and sides? I have some leftover ganache that I’m trying to use up. I thought I might make a half-recipe in a round cake pan? Wasn’t sure if it would be too rich?
Sam
Hi Emma! That sounds delicious! 🙂
Renee
I definitely want to make this! Would it impact it too much if I cut the sugar in half? I cannot use alternate types of sugar but don’t know if cutting the sugar that much means I would need to adjust other things in the recipe as well.
Sam
Hi Renee! Unfortunately, I haven’t tried reducing the sugars that much so I can’t say for sure how it would work. 🙁
Renee
Thank you for the reply!
Cathy In Texas
Absolutely delicious. Best ever peanut butter cake. Love it.
Sam
I’m so happy to hear this, Cathy, thank you so much for trying my recipe!
Diana
Hi Sam,
Could this batter be used to make a two layer 8 or 9 inch cake?
Sam
Hi Diana! I think it could work. 🙂
Vicky
This cake is so delicious!! I am not a peanut butter dessert fan, but I made it for my grandkids. I couldn’t stop eating it 🙂 I won’t make this again unless for a party, or I can give it away because it was so good I couldn’t stop eating it!
Sam
I’m so glad you enjoyed it so much, Vicky! I am definitely guilty of having more than my fair share of the cake when I’ve made it. 🤣 Happens to the best of us. 🙂
Terry Hanusik
Hey Sam, I baked this last night for a golf outing this weekend. For a true sheet cake, it definitely should be made in a 10×15. The 9×13 was much too small and the icing ran off the cake making a yummy mess. It tastes great!!! But I don’t think I would call it a “sheet” cake. I had a 10×15 I could have used but I didn’t think I should, however if I would have read through the notes, I certainly would have.
Sam
I’m glad you were still able to enjoy it, Terry! 🙂
Faith
What kind of oil and butter (unsalted or salted) did you use for the sheet cake?
Sam
Hi Faith! I use unsalted butter and any neutral cooking oil will work. 🙂
Amanda C Haussmann
Hi! This cake looks amazing and your recipes have always been a homerun – both ease of making and taste wise!
could the cake be made ahead of time, wrapped, and frozen prior to the event and be ok? frozen in the pan? then when ready to use, defrost, then frost ,and serve?
Sam
Hi Amanda! I haven’t tried freezing it but I think it should work just fine. It’s probably easiest to freeze it in the pan just make sure it’s wrapped tightly. I would freeze it unfrosted and frost once the cake is no longer frozen. 🙂
Rachel
So excited to find this recipe! Perfect for my husbands birthday!
Sam
I hope he loves it! 🙂
Ellen Manalo
Hello Sam! I’m a new fan from the Philippines 🙂 Can i possibly bake this in a 9×13 pan? Thanks in advance for replying.
Sam
Hi Ellen! I think that a 9×13 pan would work just fine. Bake it on the same temperature (350F/175C) but it will most likely need to bake for a little longer since it will be a thicker cake.
Enjoy! 🙂
Mikaru86
Tried it last week, turned out amazing (http://imgur.com/a/AgH46), can highly recommend it!
Sam
Yay! So glad you liked it, and thank you for sharing the pic — I love how you did the frosting! 🙂
Ruby & Cake
This looks insane!Is there a better combination that peanut butter and chocolate? x
Sam
If there is, I haven’t found it yet 😉
Thanks for commenting! 🙂
Sally
Hi I’m looking to make cupcakes, how many do you think this recipe would make? Also did you use the weight measurements listed when making this cake as I believe a cup of sugar is 200g but here it is listed at 150g?
Thanks!
Sam
Hi Sally! I’m not sure how this would turn out as cupcakes. I think it will turn out, but I haven’t tried it to be sure. I’m sorry about the confusion on the sugar. You are correct. A cup of sugar is 200g. This recipe has been tested with both measurements and it works well with either 200g or 150g. If you do try it I would love to know how it turns out. 🙂
Deb
Oh my goodness, this cake looks heavenly!! I could absolutely eat the frosting by the spoonfull!! Thanks for sharing the recipe, Sam! 🙂
Sam
Oh I might have had a few spoonfuls of the frosting myself 😉
Thanks so much for the kind words, Deb! Have a lovely day! 🙂
Sues
This looks soooo incredible. I could probably eat like half this cake right now- dangerous!! I definitely do not make sheer cake nearly enough!
Shelby @ Go Eat and Repeat
This is making my mouth water! I probably shouldn’t have decided to visit blogs while I’m fighting off a major sweet tooth. I love Taste of Home recipes- I’ve gotten a lot of great things from them! And that frosting looks perfect- so cool to see a little of each flavor!