Old-Fashioned Peanut Butter Icing
Transform an ordinary yellow cake with this delicious sweet and nutty old-fashioned peanut butter icing recipe. It’s a must-make for peanut butter fans!
Today, I’m sharing a recipe with a big old root system behind it: yellow cake with old-fashioned peanut butter icing. The cake we’re going to use is just a boxed mix because spoiler: it’s not the cake that is important here, it’s the icing. This is my grandmother’s old-fashioned peanut butter icing recipe to be exact and it will forever remind me of my great aunt, Red.
Now, most old-fashioned icing recipes are of the boiled icing variety. If this technique scares you, don’t worry, I’ve included lots of tips for success below to make sure you nail it every time. Trust me, when you get it right and give it a taste, you’ll want to make it again and again. Who can resist a thick layer of sweet yet nutty peanut butter icing on their favorite cake? Certainly not me! The best part of boiled icing is that you pour the hot icing onto the cooled cake and it hardens like fudge… YUM!
To make my peanut butter frosting, you’ll need creamy peanut butter (of course), as well as icing essentials like granulated sugar, vanilla, milk, shortening, and butter. So grab those ingredients and get ready, because I just know you’re going to love this old-fashioned peanut butter icing recipe as much as I do!
Recipe Ingredients
- Sugar
- Shortening (I use coconut oil these days)
- Peanut butter
- Milk
- Vanilla extract
- Unsalted butter
How To Make Old-Fashioned Peanut Butter Icing
In a large saucepot, combine sugar, milk, shortening, margarine, and salt.
Bring to a rolling boil over medium-high heat, stirring constantly to prevent scorching.
Once it reaches a boil, let it boil for two to three minutes without stirring.
Remove from heat and immediately stir in the vanilla and peanut butter.
Beat until icing is smooth and starts to lose its shine.
Immediately pour it onto the baked and cooled cake.
Allow it to cool before serving.
Look at that nice layer of peanut butter fudge icing!
Can you see why yellow cake with old-fashioned peanut butter icing is such a special cake?
This is a sight to behold.
Guess what? It seems like it was a gift from above, but as a precious reminder of my past and its connection to the future, this is my daughter’s favorite cake.
Now excuse me while I dig into this delicious slice of yellow cake!
Storage
Store leftover cake in an airtight container in the fridge for up to 1 week.
Recipe Notes
Here are my tips for success when it comes to boiled peanut butter icing:
-
- The boiling of the icing is the most critical step. Make sure it comes to a rolling boil and then stay right there, timing it. I suggest adding one minute to be on the safe side but don’t go over this as the icing will scorch.
- You absolutely must have your cake done and ready the moment the icing is done.
- Once your icing is finished, remove it from the heat and use a wire whisk to quickly stir in the peanut butter and vanilla until the icing thickens a bit and starts to lose some of its shine. It should still be pourable.
- Don’t try to spread the icing once you’ve poured it. Instead, pour it evenly over the cake so that no spreading is needed.
- Most importantly, unless you lived through the Great Depression, I strongly encourage you not to use this on anything other than a sheet cake. Only those who have the crown of wisdom that comes through age and hardship can ice a layer cake with this.
- If you want more peanut butter flavor, sprinkle the cake with roasted peanuts or crushed nuts.
- Natural peanut butter doesn’t work as well as regular peanut butter in this recipe.
- For creamier icing, you can substitute the milk for buttermilk.
Recipe FAQs
What other cakes work well with old-fashioned peanut butter icing?
You can use any kind of boxed cake mixes, such as vanilla cake, angel food cake, golden cake, white cake, or even chocolate cake (which will suit Reese’s Peanut Butter Cup fans). But if you’re looking for a homemade cake recipe, Aunt Sue’s easy pound cake would be perfect with this peanut butter icing.
Check out these other irresistible icing recipes:
Italian Cream Cake with Pecan Cream Cheese Icing
7-Minute Frosting (Foolproof Recipe)
Vegan Sweet Potato Cake With Maple Cashew Icing
Cappuccino Cake With Cappuccino Buttercream Frosting
Ingredients
- 1 Duncan Hines yellow cake mix made according to package directions and cooled
- 1.5 cups sugar
- 7 tablespoons whole milk
- 2 tablespoons shortening
- 2 tablespoons unsalted butter
- 1/4 teaspoon salt
- 1 teaspoon vanilla extract
- 1/2 cup creamy peanut butter
Instructions
- Prepare cake mix in a 9x13 baking dish as directed on the package. Allow it to cool.1 Duncan Hines yellow cake mix
- In a large saucepot, combine sugar, milk, shortening, butter, and salt. Bring to a rolling boil over medium-high heat, stirring constantly to prevent scorching.1.5 cups sugar, 7 tablespoons whole milk, 2 tablespoons shortening, 2 tablespoons unsalted butter, 1/4 teaspoon salt
- Once it reaches a boil, let it boil for two to three minutes without stirring.
- Remove from heat and immediately stir in vanilla and peanut butter. Beat until icing is smooth and starts to lose its shine. Immediately pour it onto the cake and allow it to cool before serving.1 teaspoon vanilla extract, 1/2 cup creamy peanut butter
Nutrition
This post was originally published in July of 2008. I updated the photos in August 2019.
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Hi Southern Plate! I have made your recipe three times and the icing ends up being thick immediately after stirring in the peanut butter and vanilla extract. I do the recipe exact. I don’t know if it’s the ingredient brands I’m using or what. I’m using: Clover Valley vanilla extract, Crisco shortening, 2% milk, imperial butter, great value pb and granulated sugar. Please help I have no idea what I am doing wrong.
Hi Tracy,
Hope this helps…
The boiling of the icing is the most critical step. Make sure it comes to a rolling boil and then stay right there, timing it. I suggest adding one minute to be on the safe side but don’t go over this as the icing will scorch.Â
You absolutely must have your cake done and ready the moment the icing is done.Â
Once your icing is finished, remove it from the heat and use a wire whisk to quickly stir in peanut butter and vanilla until icing thickens a bit and starts to lose some of its shine. It should still be pourable.Â
Don’t try to spread the icing once you’ve poured it, instead, pour it evenly over the cake so that no spreading is needed…
Let me know how it goes
Just what I was looking for to honor the dads in our family on Father’s Day. Many great memories attached to this frosting. Thank you!
Wonderful to hear. Hope you enjoyed the recipe and the memories!
Loved your narrative as much as I loved the recipe. I can so relate to this story, and, like you, I cherish those memories! Thanks for the trip down memory lane and the little tear I shed as I went there.
Ah,thank you kindly! Am so glad that this touched your heart 🙂
Awe, thank you Jenny for letting me know this touched your heart. Memories are such blessings aren’t they!
I loved this endearing story as much as I loved the peanut butter icing. I don’t usually post on blogs, but this story was worthy of being remembered even though it was 12 years ago that it was posted. Recipe came in my email and here I am! Thank you for sharing so many family stories. God has truly blessed you, friend!
Thank you so much for your kind words. I am so glad the story spoke to you. Thank you for being a part of our Southern Plate Family!
Good Afternoon friend, It was my day for Bible Study snacks and I made peanut butter cake with peanut butter frosting. A friend asked “is this Christy’s recipe that she had in the newsletter today” I hadn’t seen your recipe so after church I came to check it out. It is about the same thing, except I did not cook my frosting for so long. Guess great minds and tastes buds run in the same manner. Miss you and think of you often. Dianne in Gardendale….you know which one.
LOL, seems so Dianne! Hope you are well, miss you too!!
Christy I have made this cake for years. But when I make it I poke holes in the cake before icing. This way some of icing sinks into the cake and makes even more delish. Thanks for all you do. Thank you!
Great idea!!
Hi I love your recipes, I was wondering if coconut oil be used in place of the shortening when making the Peanut Butter icing?
Hey Dee! I think it would do okay. Ive not tried it and there might be a small difference but I feel like it would be fine. Please let me know if you try it!
Hi! May I know if we are to substitute the shortening with coconut oil, is the measurement still the same? Thank you for sharing!
Any vegetable shortening will do and it would be the same measurement 🙂
Can I use butter instead of shortening?
You sure can. It’s a 1:1 swap.