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.
I just have to tell you, I had the best afternoon thanks to this cake, a cup of coffee and your Southern Plate cookbook.
I had been waiting for the cookbook to become available at the library and FINALLY it came in. Money is tight so last night I was wandering through the pages looking for something sweet I could make with what I had on hand.
I saw this cake and knew I had to make it! I had everything on hand and easily whipped it up. I put my little one down for her afternoon nap and served myself a plate, with a cup of coffee and sat to read more of the cookbook. It made for the perfect relaxing nap break!
Thank you so much for sharing your wonderful recipes and your family stories. I have been writing down my family recipes for some time now and I hope you don’t mind but I have already written about 10 of yours into it as well. I have been on the site for some time and all your recipes have become favorites.
I just made this and it is absolutely heavenly 🙂 I couldn’t even wait for it to cool before trying a piece (I had already been cleaning the icing pan)… Yum! Yum! Yum! No wonder Red wanted Lucille to make her cake, this is waaaaayyy better than any bakery cake!! Thank you so much for this recipe!! Hubby loves peanut butter… He’s gonna really like this!! Thanks again 🙂
I made this for a Teacher Appreciation luncheon yesterday. I knew the cake would be good, but I had no idea about the kind of emotions it would stir. I can’t even recall how many people said “that’s just like my grandmother used to make” or “I haven’t had this in years” or “my mother always made that for my birthday.” One woman was almost brought to tears when she recalled her mother boiling the icing. She said her mother now has Alzheimer’s and couldn’t remember the recipe when she asked for it. Someone else said, “I thought that recipe had died with my mother.” After each comment, I was proud to tell them each about your blog and the great stories and recipes that you share each week. I was also proud to share memories of my Mama making this cake for me each year on my birthday and how blessed I am to still have her living. Anyway, I just wanted you to know how much I appreciate your wonderful recipes, thoughtful anecdotes and for helping me bring back (and create new!) wonderful memories.
I have been looking for this recipe for years! My Gram always used this on a homemade white cake. She has passed and no one could remember the recipe. This is very similar to the recipe I use for peanut butter no bake cookies, just without the oatmeal. Thank you! I love reading your memories!
I am so glad you found it too Nic!! Can’t wait to hear what you think!
Oh my gosh this sounds so yummy and my husband is a peanut butter lover. Gotta try this soon.
do you have a good recipe for old fashioned cooked caramel icing?
Thank you soo much!
This recipe is an answer to a prayer for me!
You have literally saved me who knows how many hours trying to invent this frosting recipe!
I promised my mom to try to duplicate her grandmothers cake for her 60th birthday.
I never knew either of my great grandmothers and only one of my grandmothers so many of our families traditions and recipes have been lost.
I am positive this is the same frosting recipe because mom says her grandmother never made “fancy” cakes with whipped frosting and “she only used poor peoples ingredients”. Another reason I am sure it is the same one is that she said her grandmother poured the icing on the cake right out of the pan.
I will have to “invent” the cake recipe because mom says that the cake part that her grandmother made was not very sweet. I am guessing maybe just less sugar like the budget cake recipe in my 40’s cookbook.
You have just made it possible for my mom to re-live a special part of her childhood. (Which couldn’t have happened at a better time since she is kinda depressed about turning 60.)
God bless you for helping keep these important parts of our heritage alive.
Laura