Old-Fashioned Peanut Butter Icing
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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! And if you don’t love peanut butter check out Boiled Chocolate Icing
Recipe Ingredients
- Sugar
- Shortening (I use coconut oil these days)
- Peanut butter
- Milk
- Vanilla extract
- Unsalted butter
Helpful Kitchen Tools
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:
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- 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.
LOVE this story and recipe. Have used the recipe often for years. It has become my family’s favorite birthday cake.
It is my families favorite as well Jo!!
This story made me cry. I am planning to make your Peanut Butter Fudge Iced Brownies tomorrow, but when I read your recipe I knew I wanted to know the story behind your icing. Thank you for the wonderful recipe and the heart warming story!
🙂 Thank you for checking it out Dana!!
I need a recipe for candy yams. I love peanut butter I will bake this cake for dinner to night. Yummy!!!.
Warning: there was a comment that said she used this for a layer cake. DO NOT do that! I now have a ruined, ugly cake and my father is coming for his birthday tomorrow. It’s late at night and I have to make a whole cake and icing all over again. The icing tasted nice but it is DEFINITELY not suited for a layer cake. It pulled crumbs from the cake as it rolled down so you could see them. Then it softened the cake so much that it broke the side of the cake. I tried to fix it, it just looks so horrible I am so upset right now. I’m sure it makes a great sheet cake. Follow the recipe as written. Don’t let me sway you from trying it, I’m sure the sheet cake version is great. But as a layer cake it just cost me time, money and frustration. My own fault for following the comment.
Oh Alex, I’m so sorry that happened to you! Thats why I never make this as a layer cake. My grandmothers could, but it takes years of practice and a lot of speed and skill to make it happen – I am not that good! I do hope y’all enjoyed the cake anyway. The company and the thought are what produce the best food 🙂
I recently asked my sweetheart of 30+ years what I should make for dessert for Sunday dinner. He said my grandmother used to make this yellow cake with peanut butter frosting, he said well more like fudge not frosting, but no one in the family has the recipe. I found your blog and recipe and surprised him on Sunday with the cake. He was so excited, he said this is just like my grandma’s!! Thank you so much for sharing your recipe and and your story. I think we all have a “Red” in our family!!
Thank you so much for posting this! This is the same exact recipe that my great grandmother made and I fell in love with it as a child. The icing is so delicious! I’m making it right now! Mmm.
I am sure we are long lost sisters! lol Love this site…Seriously, it is like reading about my family and cooking my Mom’s food! 🙂 Keep up the good work!