Peanut Butter Fudge Iced Brownies
One bite of these Peanut Butter Fudge Iced Brownies is all it takes to understand why they’ve been a longtime favorite! The old-fashioned boiled peanut butter icing creates a thick, candy-like layer over fudgy brownies for a decadent treat that tastes like it came straight from grandma’s kitchen. Make it once and it’ll be in your regular rotation!

Brownies + Peanut Butter Fudge Icing = A Match Made in Heaven
This icing has been a family staple since I first shared it on Southern Plate back in 2008… and honestly, I’ve lost count of how many of you have made it since!
We’ve always done it over yellow cake, but the day I poured it over brownies, everything changed. A dense, fudgy brownie is the perfect base for this old-fashioned boiled peanut butter icing.
These peanut butter fudge iced brownies perfectly combine rich chocolate with a thick, candy-like peanut butter topping. It’s a combination that feels like it was always meant to be, and once you try it, you’ll wonder why you ever had brownies any other way!
Ingredients
- Boxed brownie mix
- Sugar
- Milk
- Shortening
- Margarine
- Salt
- Vanilla
- Creamy peanut butter
Frequently Asked Questions
I usually get Kroger or some other generic brand – nothin’ fancy here! I’d go for whatever is cheapest where you shop because I’ve never met a brownie mix I didn’t like 😊.
You don’t have to use two boxes of mix, one is fine and you get to taste more of the icing!
To make your brownies thicker, use two boxes of brownie mix. This is how I like to do it! If you do this, you need to cut your oven temperature down to 325°F and add about 15 minutes to the baking process.
Of course! You can use your own recipe or I recommend my friend Susan Spencer’s Grandmothers recipe for Blue Ribbon Brownies. The peanut butter icing will take on the star of the show so go with whatever you prefer and what you have time for, but as for me and my house, we will make them from a mix today.
How to Make Peanut Butter Fudge Iced Brownies
Step 1: Preheat the Oven
Preheat your oven to 350°F and spray a 9×13 or 8×8 inch baking pan.

Tip: If making an 8×8 inch pan of brownies, I’d still use this same amount of icing and just let it be thicker.
Step 2: Mix & Bake Your Brownies
First, you’ll need to whip up some brownies. Just follow the directions on the package. Once they’re baked, let them cool completely before you start on the icing.

Step 3: Make the Icing
Place your milk, sugar, shortening, margarine, and salt in a good sauce pot and put this over medium heat.


Stir constantly while you wait on all of it to melt and come to a boil. Then stop and let it boil on its own (no stirring) for 2 minutes.

Step 4: Beat it, Spread it, & Serve
Remove from heat and stir in your vanilla and peanut butter.


Beat that until it’s nice and smooth, then spread it over your brownies as fast as you can.


Now allow for the icing to cool and set on your brownies. You can occupy yourself during this time by licking the sauce pot clean once it cools enough to let you 😉.
Serve & enjoy!
How to Store Peanut Butter Fudge Iced Brownies
Store your delicious Peanut Butter Fudge Iced Brownies in an airtight container at room temperature for up to 3 days. Alternatively, you can store them in the refrigerator for up to 5 days.

Ingredients
- 1 box brownie mix prepared according to package directions*
- 1-½ cups sugar
- 7 tablespoons milk
- 2 tablespoons shortening
- 2 tablespoons margarine
- ¼ teaspoon salt
- 1 teaspoon vanilla
- ½ cup creamy peanut butter
Instructions
- Prepare brownies according to package directions and allow to cool completely before beginning icing.
For the Icing
- In a heavy saucepot, combine the sugar, milk, shortening, margarine, and salt. Bring to a rolling boil while stirring constantly.
- Once it reaches a rolling boil, stop stirring and let it boil for two minutes or until it reaches the soft ball stage (I don’t use a thermometer, I just let it boil for two minutes).
- Remove from heat and quickly stir in the vanilla and peanut butter. Beat until smooth and quickly spread over the brownies.

My icing was gritty…did I not cook it long enough?
The taste was amazing, the texture…YUCK! 🙂
Okay. After drooling over these for a day and a half my pb icing was a flop. It never got creamy. Afetr I added the peanut butter it turned fudge like. I went a head and used it but it was so darn ugly I had to cover it up with chocolate frosting. So mine are more like a pb filled brownie. I can’t wait for my kids to try them after school.
Holy Goodness! So glad I had everything to make this. Heavenly, Christy. Thanks for sharing/reminding…I’m so grateful Wal Mart has yellow cake mixes on sale for 75 cents!!! 😉
OH MY! That is such heaven!
omg, I have made these many times with your peanut butter icing, and of course I always use box mix! These are to die for, yummy!!! (and yes I lick the the spoon and clean out the pot, after it is cooled b/c it is darn hot at first…won’t tell ya how I know that!!!)
~giggles~ I learned that lesson too. Experience can be scalding at times. 😉
After liking you on facebook and trying this recipe, i ordered your cookbook today on Amazon. The brownies are delicious!
Now why didn’t I think of this?! I love your PB icing, it’s great on your Black Velvet Cake. I like the way you think- doubling up the boxes of mix! Also I like that the recipe uses brownie mix, I’ve never had a homemade brownie as good as one from a mix. That’s just how it is!