Give your next batch of brownies an instant upgrade with this easy brownie frosting! It's thick, fudgy, and rich, making it the best chocolate frosting for brownies!

Why I Love This Chocolate Frosting for Brownies
- It's easy: Yes, we are all about the easy here, and this chocolate frosting is simple as can be. If you can make a boxed brownie mix, you can make this brownie frosting recipe.
- It's delicious on boxed brownie mix or homemade: Speaking of boxed brownie mix! This frosting also gives any boxed mix an upgrade (Ghirardelli triple chocolate brownie mix is my personal fave!), but it's also perfect with your favorite homemade brownie recipe. You can even use it on my homemade cosmic brownies!
- It's rich & delicious. So. Good. This brownie frosting is way better than canned store-bought, with a supremely fudgy texture and rich chocolate flavor.

Tips & Ingredient Notes
This is just an overview, click here to jump down to the full recipe card for the recipe amounts and condensed recipe instructions.
- Unsweetened cocoa powder: I use Hershey's cocoa powder, which will give you that classic chocolate flavor. Just be sure not to use hot cocoa mix, which is something entirely different!
- Butter: I like using unsalted butter for this recipe. This helps you control the level of salt, and therefore the flavor of the brownie icing.
- Powdered sugar: no substitutions can be made here, as we need the fluffy powdered sugar to make the buttercream.
- Vanilla Extract: enriches the flavor but can be omitted in a pinch
- Salt: this enhances the chocolate flavor and helps tone down the sweetness of the powdered sugar
- Milk: we use milk in this recipe to help thin it out; you can use any type of milk or cream

Flavoring Ideas for This Brownie Icing Recipe
Want to add some flavor to your brownie topping? Try these ideas.
- Peanut butter: Add 3 tablespoons of peanut butter. You can also top this peanut butter frosting for brownies with Reese's pieces or chopped peanut butter cups!
- Mint: Add ½ teaspoon of peppermint extract. Top this mint frosting for brownies with crushed peppermint candies!
- Coffee: add 1 teaspoon of espresso powder or substitute the milk for cooled liquid espresso
- Cosmic Brownies: Use this frosting on my homemade cosmic brownies or just use it on a batch of boxes of brownies with rainbow chip sprinkles!

How to Make Chocolate Buttercream Frosting for Brownies:
- Beat ½ cup of softened unsalted butter, 2 teaspoons of vanilla extract, and ¼ teaspoon of salt in a microwave-safe mixing bowl until the mixture is smooth and creamy.
- Reduce the mixer speed to low, then slowly add ½ cup of cocoa powder and 2 cups of powdered sugar.
- Stop to scrape down the sides if needed, then add 2 tablespoons of milk and beat on high for a minute or two. At this point, you can add another tablespoon of milk to make it thinner, more powdered sugar to thicken it up, or move onto the next step.
- Heat the frosting in the microwave for 15 to 30 seconds, then stir until smooth.
- Spread it onto a 9x13 pan of brownies.
Tip: Microwaving this fudge frosting for brownies makes it glossier and easy to spread!

Storage & Freezing
Storing: You can cover the bowl (press the plastic wrap directly onto the frosting) and store this brownie frosting in the fridge for up to a week. You'll need to warm it up in the microwave again & stir it before you use it.
Freezing: Chocolate frosting for brownies can be transferred to a freezer bag or airtight storage container and frozen for up to 2 months. Let it thaw in the refrigerator, then heat it in the microwave before frosting your brownies. You may need to add a splash of milk or whip it in the mixer to help it come back together.

Frequently Asked Questions:
The high sugar ratio in buttercreams like this makes the milk & butter shelf stable for 1-2 days. If it makes you feel better, store your frosted brownies in the fridge or wait to frost until closer to serving.
You do need some kind of powdered sweetener to make chocolate icing for brownies. If you can't eat sugar, or you're avoiding it, you can try a powdered sugar substitute like Swerve instead (I haven't tested it myself).
This frosting is nice & thick and will firm up in the refrigerator. Although the sugar to milk ratio makes the frosting shelf stable for a few days, store your frosted brownies in the fridge for peace of mind.
You should let your brownies cool completely before you frost them. This keeps the frosting from getting greasy and it prevents the brownies from getting crumbs in the frosting.

The Best Chocolate Frosting for Brownies
Ingredients
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Instructions
- In a microwave-safe mixing bowl, beat the softened ½ cup unsalted butter (1 stick), 2 teaspoons vanilla extract, and ¼ teaspoon salt on medium-high speed for 1 minute until smooth. Turn the mixer to low speed then slowly add the ½ cup unsweetened cocoa powder and 2 cups powdered sugar. You may need to stop and scrape down the sides. Add 2 tablespoons milk.
- Beat on high for 1-2 minutes until creamy and the frosting is at a good consistency to pipe. If it looks too runny, add more powdered sugar. If it looks too stiff, add another 1-2 tablespoons milk until you get to the desired consistency.
- Place the mixing bowl in the microwave and heat for 15 to 30 seconds, or until glossy, easy to stir and smooth.
- Spread the frosting onto a 9x13 pan of brownies.
- Although the sugar to milk ratio makes the frosting shelf stable for 1-2 days, you may want to store your frosted brownies in the fridge for peace of mind.




Icing was perfect for the brownies used at family reunion. Everybody loved them. Thanks for sharing.
SO happy to hear everyone loved this recipe, Jane! Thank you so much for taking the time to leave a review!
So glad I found this recipe! Easy yet delicious! Instead of brownies, I used it on a chocolate cake. Just enough for a nice even layer. Will make it again for sure. Thanks!
Yum, I bet it was delicious paired with the chocolate cake! So glad you loved it! Thank you so much for leaving a review, Mary!
Super easy frosting recipe and it was a big hit on the brownies I made. I did pop my frosted pan of brownies in the freezer for 10 minutes to firm up the frosting quickly for my waiting family!
Glad to hear you enjoyed this recipe, Tillie! Thank you so much for leaving a review!
Great recipe. Made our boxed brownies extra special with the homemade frosting. My kids loved it!
Glad to hear the fam loved this recipe, thank you so much for leaving a review!
This frosting was good, it seemed a little strong on the chocolate factor since it was on fudgy brownies. But I was told I was crazy! LOL I will make again but I believe I will cut back on the cocoa just a tad.
Lol, it is most definitely chocolatey! :) Thanks for leaving a review, Beverly!
This is, hands down, The best chocolate frosting!
Thank you so much for leaving a review, Katheryn!
Perfect ! Just what I needed for my dark brownies!
Thank you so much for taking the time to leave a review, Julie! I really appreciate it!
This was good! Halved it for smaller batch. Will use it again.
Thank you so much for taking the time to leave a review, Karen! I really appreciate it!
Delicious and creamy!
I’ll be using this recipe again
A great compliment to my brownies. Just what they needed. Quick and easy to make Recipe is easy to follow.
Thank you so much for taking the time to leave a review! I really appreciate it!
I made this frosting for my milk chocolate brownies when I had company over, and everyone commented on how good the brownies were, especially the frosting! Some of them wanted my recipe, so I showed them where they could find your recipe!
Yay, so happy to hear everyone loved this recipe, Sue! Thank you so much for sharing the recipe and for leaving a review, I really appreciate it!
Was good. It did rescue my brownie recipe which I forgot to mix my chocolate chips into the batter. Good enough recipe that i might firget chocolate chips next time too!
Thank you so much for leaving a review, Ray! I really appreciate it!
Great recipe for frosting a pan of brownies.
Thank you so much for leaving a review, Melanie!
Super easy to make and so much better than bought frosting! Very tasty and easy to spread!
Thank you so much for leaving a review, Sue!
Made this today and it was awesome. Thank you
VERY good frosting recipe; quick and easy. Microwaving it before frosting is a great tip. Really made it much easier to spread even tho I flip the pan over and frost the bottom rather than the top to keep the crumbs from mucking it up. Makes quite a bit more than I needed for one 13 X 9 pan of brownies but I'll freeze the rest for later.
So glad to hear you enjoyed this recipe, Mary! Thank you so much for leaving a review, I really appreciate it!