Chocolate Sheet Cake with Peanut Butter Frosting

Fudgy, beyond rich chocolate sheet cake topped with the creamiest peanut butter frosting. Feeds a crowd!

Fudgy, beyond rich chocolate sheet cake topped with the creamiest peanut butter frosting. Feeds a crowd! Easy recipe on sallysbakingaddiction.com

Happiest of Fridays to you!

I saved a good one for today. I figured we can always use more peanut butter and chocolate on the weekend. Especially if that chocolate is rich beyond belief, that peanut butter is in the form of frosting, and that cake is the size of Texas.

And, of course, all those jazzy toppings.

TGIF.

Fudgy, beyond rich chocolate sheet cake topped with the creamiest peanut butter frosting. Feeds a crowd! Easy recipe on sallysbakingaddiction.com

I’m so excited because I’ve never shared a chocolate sheet cake recipe on my blog before.

I’ve made this chocolate sheet cake a handful of times for various parties and I remember making it for an office party back when I worked in an office. And the entire thing disappeared in about .04 seconds. People flocked to it like it was a pot of shimmering gold under a rainbow.

How to make the best chocolate sheet cake! Easy recipe found on sallysbakingaddiction.com

How to make the best chocolate sheet cake! Easy recipe found on sallysbakingaddiction.com

Some cake things you’ll need to know:

The first step we’ll do is melt down some butter with water and cocoa powder on the stovetop. This helps dissolve and hydrate the cocoa powder, which typically tends to dry cakes out. This also helps bring out the cocoa’s flavor. When mixed with a cup of butter, we have some seriously delicious chocolate liquid. Instead of water, you can use black coffee (like my favorite chocolate cake!). It’s completely incredible and truly deepens that chocolate flavor.

Then we’ll mix in all with dry ingredients. The usual suspects like flour, baking soda, and salt. Whisk eggs, sugars, and vanilla extract in another bowl. Combine all of these mentioned ingredients together, then whisk in some buttermilk.

How to make the best chocolate sheet cake! Easy recipe found on sallysbakingaddiction.com

All of this chocolate magnificence goes into a half sheet pan.

Since it’s a thin cake, the bake time is quick. Which means it won’t take long to cool, either. Which obviously means that you can cut into this chocolate cake and fall immensely in love sooner. But before all that, let’s frost it with the most unbelievable peanut butter frosting on the planet. It’s my go-to peanut butter frosting recipe, just made larger because this cake is enormous!

The BEST and creamiest peanut butter frosting!! Easy recipe on sallysbakingaddiction.com

↑ ↑ Best peanut butter frosting to ever grace this earth.

Fudgy, beyond rich chocolate sheet cake topped with the creamiest peanut butter frosting. Feeds a crowd! Easy recipe on sallysbakingaddiction.com

One bite = super moist, fudgy, tender, and decadent with a party of texture on top in the form of: peanut butter cups, melted peanut butter, chocolate sprinkles, peanut butter chips, and more.

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Chocolate Sheet Cake with Creamy Peanut Butter Frosting

  • Author: Sally
  • Prep Time: 30 minutes
  • Cook Time: 20 minutes
  • Total Time: 2 hours, 50 minutes
  • Yield: serves 25-30
  • Category: Cake
  • Method: Baking
  • Cuisine: American

Description

Fudgy, beyond rich chocolate sheet cake topped with the creamiest peanut butter frosting. Feeds a crowd! I encourage you to read the full recipe and the recipe notes before beginning so you’re completely prepared.


Ingredients

  • 1 cup (230g) unsalted butter
  • 1 cup (240ml) water
  • 1/2 cup (42g) unsweetened natural cocoa powder (not dutch-process)
  • 2 cups (250g) all-purpose flour (spoon & leveled)
  • 1 teaspoon baking soda
  • 1/4 teaspoon salt
  • 2 large eggs, at room temperature
  • 1 cup (200g) granulated sugar
  • 1/2 cup (100g) packed light brown sugar
  • 2 teaspoons pure vanilla extract
  • 1/2 cup (120ml) buttermilk, at room temperature*

Peanut Butter Frosting

  • 1 and 1/2 cups (405g) creamy peanut butter (do not use natural style)
  • 1/2 cup (115g) unsalted butter, softened to room temperature
  • 3 cups (360g) confectioners’ sugar
  • 1/2 cup (120ml) heavy cream, half-and-half, or whole milk*
  • 1 teaspoon pure vanilla extract
  • pinch salt
  • toppings: ½ cup (135g) melted creamy peanut butter for drizzling, 1 cup chopped peanut butter cups, handful of mini chocolate chips or peanut butter chips, and/or chocolate sprinkles*

Instructions

  1. Preheat oven to 350°F (177°C). Generously grease a 12×17 inch half sheet/jelly roll pan. Set aside.
  2. Heat the butter, water, and cocoa powder together in a large saucepan over medium heat. Whisk constantly until the butter has melted and everything is smooth and combined. Set aside. In a large bowl, whisk the flour, baking soda, and salt together. Pour the warm chocolate/butter mixture on top, then slowly whisk together until combined. It will be very thick.
  3. Whisk the eggs, granulated sugar, and brown sugar together in a medium bowl. The mixture will be thick. Whisk in the vanilla until combined, then pour into the chocolate batter and whisk until combined. Finally, whisk in the buttermilk. Pour the chocolate batter into the sheet pan.
  4. Bake for 15-20 minutes. (Mine takes exactly 17 minutes.) Use a toothpick to test for doneness: stick it into the cake. If the toothpick comes out clean, the cake is done. If not, continue baking. Remove cake from the oven and set the pan on a wire rack. Allow the cake to cool completely in the pan before frosting. The refrigerator helps speed things up, if you have room for the large pan!
  5. Make the frosting: Using a handheld or stand mixer fitted with a whisk attachment, beat softened butter and peanut butter together on medium-high speed for 2 minutes until completely smooth and creamy. Add the confectioners’ sugar, cream, vanilla extract, and salt. Beat on low speed for about 20 seconds, then gradually increase to high speed. Beat on high for 1 minute until combined and frosting is fluffy. Taste; add more salt if needed. To thicken, add more confectioners’ sugar and to thin, add more cream.
  6. Spread frosting all over cooled cake, then top with toppings. Slice and serve. Cover leftovers tightly and store in the refrigerator for up to 5 days. It’s so good cold!

Notes

  1. Make Ahead & Freezing Instructions: Cake can be made 1 day in advance, covered tightly at room temperature, and then frosted before serving. Frosting can also be made 1 day ahead of time– cover tightly and keep in the refrigerator. Bring frosting to room temperature before spreading. Frosted cake can be frozen up to 2 months; thaw overnight in the refrigerator and bring to room temperature before serving.
  2. Buttermilk: Buttermilk is required for this recipe. You can make your own DIY version of buttermilk if needed. Add 1 teaspoon of white vinegar or lemon juice to a liquid measuring cup. Then add enough whole milk to the same measuring cup until it reaches 1/2 cup. (In a pinch, lower fat or nondairy milks work for this soured milk, but the cake won’t taste as moist or rich.) Stir it around and let sit for 5 minutes. The homemade “buttermilk” will be somewhat curdled and ready to use in the recipe.
  3. Heavy Cream: Using heavy cream, half-and-half, or whole milk in the frosting produces the creamiest texture. (I use and highly recommend heavy cream.) If needed, you can use a lower fat or nondairy milk.
  4. Room Temperature Ingredients: Here is why the ingredients must be at room temperature. The butter is melted and warm, so it’s best the other ingredients are not cold.
  5. Toppings: So many toppings! Use what you like best. I also topped the cake with these Reese’s peanut butter sprinkle ice cream topping (I found it near ice cream aisle)
  6. Sheet Pan: I own and love this 12×17 half sheet pan!
  7. Cake batter adapted from All Recipes.

Keywords: chocolate sheet cake, chocolate cake with peanut butter frosting

Add this to your weekend plans.

Fudgy, beyond rich chocolate sheet cake topped with the creamiest peanut butter frosting. Feeds a crowd! Easy recipe on sallysbakingaddiction.com

Fudgy, beyond rich chocolate sheet cake topped with the creamiest peanut butter frosting. Feeds a crowd! Easy recipe on sallysbakingaddiction.com
Fudgy, beyond rich chocolate sheet cake topped with the creamiest peanut butter frosting. Feeds a crowd! Easy recipe on sallysbakingaddiction.com

142 Comments

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  1. “Good one” is a total understatement. This looks AMAZING! I cannot wait to try this recipe. Always love stopping by!

    1. Thanks Karly! xo

  2. May I know if ur recipe for the frosting will be sufficient to frost a 2 layered 9″cake?

    1. Should be!

  3. Hi i’d like to know if this recipe can be baked in a 9″ round tin? And would it need 2 or 3 tins? 

  4. I didn’t have enough peanut butter for the frosting (I know!! Inconceivable!!) so instead I used….. NUTELLA. Amazing. 

  5. I just made this frosting for a chocolate cake. It’s a 6 layer cake and let me just let you. THIS FROSTING IS INCREDIBLE!!!! I’m obsessed with it and it reminds me of the center of the Reese’s cup. Absolutely incredible frosting!!!!!

  6. Hi there!! I know this might be a long shot, but I’m wondering about how deep you fill the jelly roll pan. I’m making this cake for about 70 folks tmrw, so I’m baking it in a 21″ x 15″ x 1″ sheet pan. I plan on doubling the recipe, but I think I’ll need a little less the full batter in the pan. Does that make sense?! So to get to my question, about how deep in this 1″ thick pan should the batter be?! About 1/2?! 3/4?! I’ll obviously have to eyeball but I don’t want to have to overflow or be too thin 🙂 

    Thanks for your time, Sally!! I make your Oreo cooking recipe for friends’ bday + they’re always a hit!! 

    1. Hi Kristen! I would fill only halfway.

  7. This frosting is amazing! I used it to top a very large batch of brownies and sprinkled pretzels on top and got rave reviews at our cattle branding. Thanks!

    1. Brownies with PB frosting and pretzels?!? Sounds amazing!

  8. Hello Sally,

    Please note that I have 9″x13″x 0.75″ Sheet Pan, so do I need to half the recipe ingredients or follow the recipe as given.

    Good luck to newer additions in your family 🙂

  9. I made this for a large crowd and it was absolutely delicious!!! There was not a crumb left in the pan. I think this was the best chocolate cake I have ever had and the frosting had plenty of wonderful peanut butter flavor!! I will definitely make this cake again!! Made it just as it was in the recipe and it was perfect! Thank you so much!!!

  10. Hi Sally,
    I want to make this cake for someone who has an egg allergy. What do you think about substituting plain unsweetened applesauce for the eggs?
    Or do you have any other suggestions?
    Thank you so much

    1. Hi Linda! I wish I could help, but I have very little experience with egg-free cakes. My immediate guess would be some applesauce though.

      1. Thank you. I’ll let you know how it turns out 🙂

  11. Hi Sally,

    This is the second time I have made this delicious cake! The first time, everything came out perfect. This time, all was well, until I had finished mixing the frosting. I scraped down the bowl, then went to do one last quick mix, and the frosting completely separated!! I could literally see beads of cream sitting on scrambled egg-looking peanut butter in my bowl of previously fine frosting! Any ideas why that would happen?

    It still tasted fine, and the cake was just for my family’s dessert for the week, so I used it anyway, but it’s just so weird!

    1. And the first time it was ok? Oh goodness! Was the butter and/or peanut butter at room temperature? Maybe a little too cold? If everything is uniform temperature, it should be smooth 🙂

      1. I think that was it. I made it again today, and made completely sure the butter was not cold, and it stayed together. Thanks!

  12. It sounds like maybe the cake was over-baked. How did it taste?

  13. Marlene Cohen says:

    Can I use this peanut butter frosting recipe to pipe on a cake? Will it hold?

    1. Absolutely!

  14. Would I need to modify the recipe to turn them into cupcakes?

    1. I’d simply make these chocolate cupcakes with peanut butter frosting instead 🙂
      But you can make this cake into cupcakes by filling the liners about 1/2 full and baking 18-21 minutes or until the tops spring back when gently pressed.

  15. Noemi Martin says:

    I would like to use either two round pans (9×1.5″) or one rectangle pan (13×9″). What do you recommend? and for how long should I bake it at?

    It is for a birthday party; crowd of 15. Thanks!

  16. Samhita Raman says:

    Hi Sally!
    I was wondering if I could double this recipe and bake it in a 12×17 pan that’s two inches deep, like this one: https://www.amazon.com/Wilton-Performance-Aluminum-Large-18-Inch/dp/B0000VMFJ8

    Thanks!

    1. Hi Samhita! I use a 12×17 inch pan for this cake. It doesn’t quite rise to the top, but I feel doubling the recipe would simply be too much batter leading to overflowing and un-even baking.

  17. This cake was simply amazing! Very rich so I could cut it into little squares and it was more than enough for everyone at work to enjoy! Thanks!

  18. Could I make and frost this a day ahead of I keep it in the refrigerator tightly covered?

    Thank you!

    1. It should be ok at room temperature if covered tightly for one day!

      1. Thank you very much!

  19. I needed a quick, easy recipe with pantry ingredients that would feed a crowd. This is it! Thank you so much for a delicious recipe. I made it exactly as directed and it was a huge hit. I will definitely be making this one again!

  20. Hi, Sally. Can this recipe be used to make 8-9 inch round cakes instead of a sheet cake? Thank you. 🙂

    1. Hi Michele! Absolutely. Though I do have a preferred chocolate cake recipe for layers if you want to try that instead.

      1. Thank you for getting back to me so quickly! I’ll check out your other recipe as well. 🙂

  21. Hi Sally! Is there any way I could make this in a 13×9? Would it come out ok? Suggested bake time if I were to do it that way? I dont have a 12×7.

    1. Hi Lydia, for a 9×13 inch chocolate cake I recommend this repine: https://sallysbakingaddiction.com/triple-chocolate-layer-cake/#tasty-recipes-68103 and see the recipe notes for instructions on how to bake in that pan.

  22. This is the best chocolate sheet cake E-V-E-R! I made it to use in your petit fours recipe, and it was AMAZING! I had one little square of just plain cake and almost ate the whole thing in one go. This cake is ridiculously good; moist, chocolate-y, soft…yummmmmmm! For someone who loves making fancy layer cakes with all the fuss and frills, I think I could easily choose this simple sheet cake over any layer cake 😀 Honestly, it really is THAT good!

  23. YUMM!! just a word of advice-make sure your frosting ingredients are truly room temp! I added my cream cold and the whole thing kind of seized up- still DELISH and I’m going to use it for buckeye’s, but in order to get that nice whipped frosting DON’T add cold ingredients 😉

  24. Ellen Cannon says:

    Hello, I would like to make this cake for my son’s graduation party. I would like to make a sheet cake; the whole thing. Would I just double the ingredients? If so, how long would I bake it and would I just turn it out of the pan after it was cool? I have never made a sheet cake before!

    1. Hi Ellen, This recipe is written for a 12×17 inch pan (https://www.amazon.com/gp/product/B008BUKO6G?ie=UTF8&creativeASIN=B008BUKO6G&linkCode=xm2&tag=sallsbakiaddi-20). I have not made this into a larger size sheet cake so I’m unsure of the exact bake time needed. You can see all of my information on how to calculate how much batter you would need and much more in my post on cake pan sizes.

      1. Ellen Cannon says:

        Thanks so much! I will check it out. If I end up doing this, I will try to post my findings here later.

  25. This was awesome. I made almost exactly as written with the addition of Reese’s pieces to the topping. Will definitely make it again!!

  26. Hello Sally,
    Can I make this into a layer cake? I’m on Corona lockdown and my ingredients are limited. I’m trying to make a birthday cake for my husband. Please advise. Thankyou!

    1. Hi Freckles, you can but I’m unsure of the exact bake time. I recommend my chocolate cake recipe.

  27. Hello – I am so eager to try the peanut butter frosting, but I’m in quarantine lockdown and only have 2% milk. Will it work with 2%? I see your notes about higher fat milk needed for texture. Is there anything else that I can add in addition to my 2% milk to make up for the texture loss? We are safe at home and baking away here! Thank you!

    1. Hi Lisa, A lower fat milk for the frosting will produce a slightly thinner and not quite as creamy frosting but in a pinch you can still use it.

  28. I made this cake twice, once with baking soda as directed and once with baking powder to see if i could get it to rise more. They both came out very flat.

    I tried to roll one of the cakes into a jelly roll to make it look more appealing but it fell apart. This cake turns out more like a bar than a cake.

    I ended up cutting one of the cakes into thirds and using the broken bits of the other cake to layer in between to get some loft.

    The flavor is good and it is very moist, and the frosting is very good. I did use natural peanut butter, I just poured off the oil and only used the more solid part of the jar and used my kitchenaid to whip the frosting. That turned out fantastic.

    To be clear, I didn’t expect a lot of loft with with cake, but it is so flat it looks off. Maybe something was off in my kitchen, but I would not make this cake again.

    1. Hi Rachael, thanks so much for your feedback and trying this recipe– I do not recommend it for a jelly roll cake. It’s a very thin cake as you can see in the photos, so I’m sorry you were disappointed. Thanks again for trying it.

  29. Oh. My. Gosh! I just made this peanut butter frosting; woah mama! It is truly THE best peanut butter frosting I have made and eaten!
    Thank you for sharing! Can’t wait for my family and friends to try it too.

  30. Hi I yeet I am wondering if any other pans would work, and if it can be two small cakes together. This is my first time making a cake and hope it will turn out ok

    1. Stephanie @ Sally's Baking Addiction says:

      Hi Yeet, For a chocolate cake that is two smaller layers see this Triple Chocolate Cake recipe.

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