This is the perfect peanut butter cake recipe. It has the great taste of peanut butter without being overwhelming. I canโt wait to make it again and share it with friends! ~Marci

This old fashioned peanut butter cake is a winner!
Peanut butter cake is a good old Southern potluck staple. It starts with a base of moist peanut butter sheet cake. Then hot peanutty frosting gets poured right over the warm cake, and the whole thing gets showered with roasted peanuts. Just. Divine.
I can’t imagine there are too many of you out there who wouldn’t enjoy this old fashioned sheet cake. I loved everything about it. Starting with the cake itself; peanut butter does something wonderful to the texture. It’s not too sweet, just the way I like it, and very pillowy and moist. And I can’t even with that frosting.
gather your ingredients
- all purpose flour
- granulated sugar
- peanut butter
- I love Jiff for its flavor and texture. Regular creamy pb works best. Natural peanut butter, the kind that separates with an oily layer at the top, doesn’t work as well for baking.
- butter
- eggs
- vegetable oil
- buttermilk
- the buttermilk in the cake and in the frosting gives this cake its Southern charm.
- confectioner’s sugar
- baking soda, salt
- vanilla extract
- crushed peanuts
The hot peanut butter frosting is like peanutty caramel, so good
If you’ve tried my Brown Sugar Peach Cake or my Pumpkin Praline Cake, you might have an inkling about this one. The frosting is cooked in a saucepan, and then literally poured right over the cake. It sets up immediately, almost like fudge or caramel. You have to work quickly, but your reward is that saucepan with a thin layer of peanut frosting clinging to the sides…Let’s just say I stood there scraping it with a spoon for an embarrassingly looooong time.
we love caramel
- Pumpkin Layer Cake with Caramel Frosting
- Caramel Frosted Zucchini Pecan Bars
- Salted Caramel Pot de Crรจme
- Caramel Apple Sheet Cake
- Caramel Apple Bundt Cake
whisk up peanut cake batter right in a saucepan!
The batter is thin enough that you can whisk it up in a saucepan, no mixer or extra bowl needed. That makes this amazing cake dangerously easy to throw together (it could get habit forming.)
the bottom line
The older this site gets, the longer my favorites list gets, but I’m looking you straight in the eye when I say this peanut butter cake is a goodie. You’ll love it, and it will serve you well if you need an easy dessert to bring anywhere this season. The 9×13 cake can serve up to 24 people, right out of the pan. Try it.
“I never bake but I made this for my son’s birthday and my whole family thinks it may be the best cake they ever ate. The frosting is so good, like a peanut butter caramel.
Thanks for a great recipe!!” ~Gerry
Peanut Butter Cake
Video
Equipment
- standard 9×13 baking pan
Ingredients
- 2 cups all purpose flour
- 2 cups granulated sugar
- 1 tsp baking soda
- 1 tsp salt
- 1/2 cup unsalted butter
- 1 cup water
- 1/2 cup creamy peanut butter Note: I used regular peanut butter for this recipe, 'natural'peanut butter does not work as well.
- 1/2 cup vegetable oil
- 2 large eggs, room temperature
- 1/2 cup buttermilk, room temperature
- 1 tsp vanilla extract
frosting
- 1/2 cup unsalted butter
- 1/2 cup creamy peanut butter
- 6 Tbsp buttermilk, you might need a touch more if your frosting is too stiff
- 1 tsp vanilla extract
- 3 cups confectioner’s sugar, sifted
garnish
- 1/2 cup roasted peanuts
Instructions
- Preheat oven to 350F and spray a 9×13 pan with nonstick spray.
- Whisk together the flour, sugar, baking soda, and salt in a medium bowl and set aside.
- Heat the butter and water in a medium/large saucepan until it comes to a boil. Take off the heat and whisk in the peanut butter and oil until smooth. Let cool for a few minutes, then whisk in the eggs, buttermilk, and vanilla until well blended.
- Add the dry ingredients to the wet ingredients, and whisk until just combined.
- Pour the batter into the prepared pan and bake for 40-45 minutes, until the top is golden and a toothpick inserted in the center comes out clean. Set the cake on a cooling rack while you make the frosting.
- To make the frosting, put the butter, peanut butter, and buttermilk in a saucepan and bring to a full boil. Take off the heat and beat in the vanilla and powdered sugar, adding a cup at a time, until the frosting is smooth. I like to put it back on a gentle heat just to rewarm it, stirring constantly, before pouring over the cake. Note: if your frosting is very stiff and not pourable, add a little bit more buttermilk to thin it out.
- Pour the hot frosting over the warm cake, working quickly because the frosting sets up immediately. Spread evenly over cake.
- Garnish with peanuts.
Notes
- Make it chunky!ย Yes, of course, go ahead and use chunky PB for this cake.ย I would still use smooth for the frosting, but that’s your call.
Can you please give timing for baking your Peanut Butter Cake in two 8″ layer pans? Thanks!
The time will be close to the same, but ovens vary, so check yours on the early side.
I make this cake all the time. When I ask if I could bring something, itโs always bring your peanut butter cake. Whatโs the best?
Currently baking it, so Iโm not sure the results. I had to last minute add the vegetable oil to my batter in the 9×13 using a fork to frantically whisk it in. You mentioned vegetable oil in the ingredients list but never included in your instructions so I completely skipped this ingredient. Thankfully I always pull out all ingredients ahead of time and so I saw it sitting on my counter and had time to pull the cake out of the oven and add it in. Please adjust this on your pageโฆ. I wonder if this is what the one commenter was missing n her cake that turned out like rubber????
The oil is in the instructions, it’s in step 3. It gets whisked in with the peanut butter. It’s possible that the other commenter missed it as well!
Help meeeee. I have made this recipe twice now, and my cake looks great and then as it cooles it sinks and comes out like rubber. I’m sad because my MIL made it and it was amazing. What am I doing wrong? Can milk be substituted for buttermilk? The first time I made it I accidentally added the wet to the dry, could that have done it? This cake is amazing and I need to figure it out ๐คฃ
It’s so hard to troubleshoot without all the info Sara, baking is such an exact science and any little change can alter your results. I would stick to the recipe exactly, including pan size and all the ingredients. Then I would also suggest chatting with you MIL to see what the difference could have been between your two versions of the cake. Feel free to email me and we can delve into it further!
For YEARS this recipe has been my go-to whenever I need something fool-proof and I know it will turn out delicious.
That makes me happy ๐
My hubby and I are peanut butter lovers and this certainly covered our cravings! Followed exactly as written,but melted some semi-sweet chocolate chips and drizzled over the top. Of course milk chocolate or white chocolate would work great too! Just wanted to dress it up a little for dinner with friends. Fantastic! Passed out the recipe to all that asked! Thanks Sue
Thanks Dawn, so happy you loved it. I’m dying to try this cake with a chocolate frosting!
Question: Can this recipe withstand vegan substitutes without it getting too liquidy? For example: I have to make vegan buttermilk using almond milk & vinegar. Vegan butter will be โthinnerโ too. How should I make adjustments? Itโs for a friend, and she is a peanut butter fanatic, so donโt want to mess it up.
It sounds great.
This is the kind of thing you need to experiment with. Plant based milk should be fine, and don’t forget the egg substitute. I like Bob’s Red Mill or King Arthur Flour egg replacers.
I love this recipe so much, I now make it a the time! We are going to have this at our next party. I was wondering what the baking time and oven temperature would be for cupcakes instead.
Thanks Elizabeth, glad you love the cake so much. I assume you could make it as cupcakes but they would be flat, moist, and dense, just like the cake. I would use parchment paper liners because they will release better from the sticky cake. The temp would be the same, and the time will depend on the size of your cupcakes, check at 15 minutes if they’re small.
Iโm going to try making this for the first time in a few days, but I was wondering if the recipe might be enhanced by substituting some other liquid for the water?
Water works perfectly in this cake, so I would try it as is.
This recipe was a hit! Itโs the new โbirthday cakeโ!
I put it in a Bundt pan and chopped up Reeseโs peanut butter cups and topped it with that instead of peanuts. Delicious.