Brownies covered with a thick layer of fudge frosting and rainbow sprinkles. The best way to jazz up a box of brownie mix!
Party Brownies
Yes, That’s What I Said. Party Brownies!
![Lindsay Ostrom headshot.](https://pinchofyum.com/wp-content/uploads/Lindsay-Post-Notes-960x960.jpg)
My sister Kristin has been making these fudgy, sprinkly, crowd-favorite brownies all summer, and I’ve sent her 100 texts to get all the info on this recipe over the last few weeks because I am obsessed with these babies.
Kids love them, adults love them, they’re easy, they’re fun, and they disappear alarmingly fast. They’re PARTY BROWNIES!
The base: a box of brownie mix. I don’t feel bad about this in the slightest. It makes these perfect “party brownies” because you can throw them together at a moment’s notice with minimal effort.
The top layer: an old-fashioned-style chocolate fudge frosting. The kind with the dry, crackly exterior, the kind my mom puts on my dad’s birthday cake every year, the kind that everybody’s grandma has a recipe for somewhere in an old stained church cookbook. It’s so good and it’s the exact top layer I never knew my brownies needed.
I call these party brownies because there is an event to bring them to nearly every weekend.
A pool party at my parents’ house, Bjork’s extended family reunion, an impromptu hangout with friends – the answer to all scenarios is a pan of Party Brownies. ♡
![Lindsay signature.](https://pinchofyum.com/wp-content/uploads/lindsay-signature-notes.png)
How To Make This Recipe
1
Make Brownie Mix.
I give you permission to use a box of brownie mix. Ghirardelli Double Chocolate is our house favorite. (affiliate link)
![Mixing brownie mix in a bowl.](https://pinchofyum.com/wp-content/uploads/Brownie-Mix-scaled.jpg)
2
Make The Frosting / Icing / Fudge Top Layer.
Boil your butter, milk, and sugar for a good 45 seconds. SET A TIMER! We don’t want to over (or under) cook this.
![Boiling butter, milk, and sugar in pot on the stove.](https://pinchofyum.com/wp-content/uploads/Boiling-Frosting-scaled.jpg)
3
Pour Frosting On Brownies.
Add chocolate chips to the boiled frosting and pour immediately over the brownies. It’s going to want to set fast, so let’s go, chop chop, no checking Instagram right now!
![Pouring frosting on a pan of brownies.](https://pinchofyum.com/wp-content/uploads/Pouring-Frosting-scaled.jpg)
4
Add Sprinkles!
Add them to the frosting immediately before it sets!
![Sprinkling sprinkles on top of a pan of brownies.](https://pinchofyum.com/wp-content/uploads/Sprinkles-scaled.jpg)
5
You’re Done. Yum.
LIKE SERIOUSLY REALLY YUM.
![Hand holding a brownie with a bite taken out.](https://pinchofyum.com/wp-content/uploads/Brownies-scaled.jpg)
Watch How To Make These Brownies
![A picture of Party Brownies](https://pinchofyum.com/wp-content/uploads/Party-Brownies-2-Square-183x183.jpg)
Party Brownies
- Total Time: 55 minutes
- Yield: 12–16 brownies 1x
Description
Brownies covered with a thick layer of fudge frosting and rainbow sprinkles. The best way to jazz up a box of brownie mix!
Ingredients
- 1 box brownie mix (usually 16–18 ounces)
- 6 tablespoons butter
- 1/3 cup milk
- 1 1/4 cups granulated sugar
- 1 teaspoon vanilla extract
- 1/2 teaspoon coarse kosher salt
- 1 cup semi-sweet chocolate chips
- rainbow sprinkles
Instructions
- Make the brownies: Bake the brownies according to package directions in a 9×13 pan or slightly smaller rectangular pan (see note 1). I usually try to let them cool for an hour before frosting them.
- Make the frosting: Melt the butter in a small saucepan over medium heat. Add the milk, sugar, vanilla, and salt; bring to a consistent boil over medium heat and cook for 45 seconds (it should be at a rolling boil for the full 45 seconds). Set a timer so you don’t overcook it!
- Mix in the chocolate: Turn off the heat and add chocolate chips and stir to combine (if there are stubborn lumps, just whisk it for a minute).
- Frost the brownies: Working quickly, pour the frosting over the brownies and spread evenly and add sprinkles. The frosting will start to set immediately, so don’t be a slow poke with this part (see note 2)!
- Rest and serve: Let the frosting rest for 15-30 minutes, depending on how clean you want your slices to be! Cut, serve, PARTY TIME!
Notes
1. A 9×13 is what my sister always uses – but I also love to use a smaller rectangular pan if you have one (mine is 10.5 x 7.5) to make the whole thing just slightly thicker. A square pan will make the frosting too thick, so I would not recommend that.
2 – If you are scrambling to find your sprinkles when the frosting starts to set on top (been there), just add the sprinkles to the dry-ish top and use the back of a spoon to gently tap them into the frosting a bit so they will hold in place.
- Prep Time: 10 minutes
- Cook Time: 45 minutes
- Category: Dessert
- Method: Bake
- Cuisine: American
Keywords: brownies, brownie mix, boxed brownies, easy brownies
What’s the salt for?
It should go in the frosting! Thanks for pointing that out. Updated the recipe!
Does the salt go in with the butter, milk, sugar and vanilla before the boil?
Yes! Thanks for catching that – updated! 🙂
Have you tried two boxes of brownies? The box says the mix should go into an 8×8 or 9×9 so I would think they would be too thin in a 9×13. I trust you though 😉
Do you need to let the brownies cool completely before frosting?
Letting them cool for an hour or so is best!
After step 2 do you take it off the heat as you add the chocolate chips? Or keep on heat? Thanks! Looks delicious!
I took the pot off of the heat when I poured the chocolate chips in and stirred. There was plenty of residual heat to melt the chips until they were smooth.
Yes, take it off the heat! We’ll add that to the recipe card to clarify!
What is your go-to boxed brownie mix? I usually have Ghirardelli triple chocolate on hand but I wasn’t sure if with the frosting that would be chocolate overload 😄
Lindsay’s go-to is the double chocolate version of that!
How can I make these ahead of time or store them?
Yes, absolutely! They’re best eaten within a day or two, but can definitely be made ahead.
This is a great recipe to make with kids! I made these with my 10 yr old son and he was able to do most of the recipe without much help. The frosting is so fudgy and decadent a small serving was perfect! I’d be proud to take these to a party and the sprinkles on top are the perfect festive touch. Also, great with a cup of coffee!
These look fantastic. Do you think that the frosting could be made with plant-based butter and almond milk?
We haven’t tested it, so can’t say for sure! Would love to hear how it goes though if you give it a try!
how to store them? how long can we store them? even if they are not meant to last long 🙂
They should store just fine covered at room temp for a day, but would refrigerate after that!
I have the same Ghirardelli box mix, but there are no instructions for baking in a 13×9 pan. How long should I bake? I have both glass and metal pans. Thanks!
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Loved these! I used the Ghirardelli mix and baked for 24 minutes in a 9×13 pan. I definitely DO NOT suggest adding flaky sea salt to the brownies before the frosting as this made some bites a little too salty with the salt in the frosting. Otherwise they were easy and delicious and everyone loved them.
These brownies were amazing! I cut the sugar in the frosting down to 1 cup. It still hardened, and they were still plenty sweet. Such an easy way to make boxed brownies more impressive!
Fudgy goodness!
Definitely a PLATE of yum! I made these using Pillsbury Dark Chocolate brownie mix and without sprinkles (☹️) because some people in my house don’t like their texture. This recipe is a keeper!
These brownies are FABULOUS!!! Everyone I have shared them with loves them!!!
Glad to hear it, Suzanne!
My brownie mix is for an 8×8 pan. Do I halve the icing recipe?
Can I make the frosting ahead of time, store it in the fridge for a day, and then gently warm to use?
This is really best done right when the fudge is done cooking – I wouldn’t recommend waiting!
I haven;t made brownies myself for quite a long time, but this recipe has got me wanting to give it a try again. Party Brownies look and sound delicious!
These are fantastic! I made these for a potluck and they were quickly devoured. I had to go home and make a second batch for my family because I need more of these brownies! These are so easy and tasty – they will definitely be added to the regular dessert rotation.
These are delicious! I think I was too worried about over cooking my frosting that it didn’t boil long enough somehow? It was quite runny. Still insanely delicious though! My daughter says the best frosting she’s ever tasted. So I guess I should practice again!