Brownie Cupcakes with Peanut Butter Frosting

Fudgy brownie cupcakes covered in creamy peanut butter frosting.

brownie cupcakes with peanut butter frosting with 1 bite taken out

What is happening?? Has it really been over a MONTH since my last peanut butter recipe?!?? So shameful.

brownie cupcakes with peanut butter frosting

Let’s just make up for that disgrace with an over-the-top, yet completely simple brownie cupcake. The cupcake itself is so fudgy and rich, that I could almost just eat it plain. But I knew these fudgy brownie cupcakes were the perfect canvas for peanut butter.

This frosting! Be still my heart. I originally planned to top these fudgy brownie cupcakes with cream cheese frosting, but let’s be serious. I immediately reached for the peanut butter jar after the cupcakes cooled. It’s a simple frosting recipe, really. And my secret ingredient is the heavy cream.

Trust me on this. Heavy cream is a frosting’s dream come true. It creates the smoothest, fluffiest frosting on earth. Plus, it makes the frosting so easy to pipe or slather on the cupcake. And yes. It is impossible not to swipe a taste from the frosting bowl.

brownie cupcakes with peanut butter frosting and chocolate sprinkles

Sidenote: I used a Wilton 1M piping tip to frost these. Feel free to just swirl the frosting on with a knife or use another piping tip. I love the 1M though… it creates pretty swirls like a soft serve ice cream cone!

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brownie cupcakes with peanut butter frosting with 1 bite taken out

Fudge Brownie Cupcakes with Peanut Butter Frosting

  • Author: Sally
  • Prep Time: 15 minutes
  • Cook Time: 8 minutes
  • Total Time: 2 hours
  • Yield: 10-12 cupcakes
  • Category: Cupcakes
  • Method: Baking
  • Cuisine: American


Fudgy brownie cupcakes topped with creamy peanut butter frosting.



  • 1/2 cup (1 stick) unsalted butter
  • 3/4 cup packed light brown sugar
  • 1/2 cup unsweetened cocoa powder
  • 1 Tablespoon pure vanilla extract
  • 2 large eggs, at room temperature
  • 1/4 teaspoon salt
  • 1/2 teaspoon baking powder
  • 2/3 cup all-purpose flour (spoon & leveled)

Peanut Butter Frosting

  • 5 Tablespoons unsalted butter, softened to room temperature
  • 1 cup creamy peanut butter
  • 1 cup confectioners’ sugar
  • 1/3 cup heavy cream
  • 1 teaspoon pure vanilla extract
  • 1/4 teaspoon salt
  • chocolate sprinkles


  1. Preheat oven to 375°F (191°C). Line a muffin pan with cupcake liners.
  2. Make the cupcakes: Melt butter in the microwave in a large microwave safe bowl. Mix in the sugar until smooth and microwave for about 1 minute. Stir the mixture until smooth again. Whisk in the vanilla and eggs. In a separate bowl, mix together the salt, baking powder, cocoa powder, and flour. Slowly add to the wet ingredients and stir until completely combined.
  3. Fill the muffin tins about 2/3 full. Bake in the prepared muffin tin for about 8-10 minutes (mine took a little under 9 minutes). Allow to cool completely.
  4. Make the frosting: Beat softened butter on medium speed for 1 minute until completely smooth and creamy. Add the peanut butter and beat on medium-high speed until the two are combined. Add the confectioners’ sugar, cream, vanilla extract, and salt. Beat on low speed for about 20 seconds, then gradually increase to high speed. Beat on high for 1 minute. Frost cooled cupcakes. Top with chocolate sprinkles, if desired.


  1. Make Ahead & Freezing Instructions: Cupcakes can be made ahead 1 day in advance, covered, and stored at room temperature. Frosting can also be made 1 day in advance, covered, and stored in the refrigerator until ready to use. Decorate/assemble cupcakes immediately before serving. Leftover cupcakes keep well covered tightly at room temperature or in the refrigerator for 3 days. Frosted or unfrosted cupcakes can be frozen up to 2-3 months. Thaw overnight in the refrigerator.
  2. Boxed Mix: You could easily use boxed brownie mix as a shortcut, but you would need to adjust the frosting accordingly since the peanut butter frosting recipe below only makes enough for 10-12 cupcakes.
  3. Quantity: Depending on how full you fill the muffin tins, you could get anywhere from 8-12 cupcakes. I fill mine about 2/3 full.

Keywords: fudge cupcakes, fudge cupcakes with peanut butter frosting


  1. Hello Sally! Would just like to drop by and let you know that your Fudge Brownie Cupcakes with Peanut Butter Frostings was a huge at my niece’s 1st birthday last week! They are absolutely mouth-watering. Also, I’d like to tell you that your blog is attractive with their bright colours and beautiful photos. Your baking directions are straightforward and easy to follow. Thank you so much! Am looking forward to future posts! – perhaps a red velvet cake for my parents’ upcoming anniversary 🙂

    1. Thank you Shaleen! This comment is so sweet. I really appreciate all the kind compliments on my blog, photos, and recipe directions! Anyway, happy birthday to your niece! I’m happy these cupcakes were a hit.

  2. Hi Sally

    Sorry if you’ve posted it somewhere and I have missed it, but would you mind telling me what the butter in the frosting is in grams? Its one of those things that google can give you many many different answers for!


    1. Hi Michelle – 5 Tbsp of butter is approximately 75 grams.

  3. Cally Younger says:

    I made these last night for my husband’s birthday. I tripled the recipe so we could share them with the high school basketball team he coaches after their game tonight! I just wanted to tell you though, that I added some crushed “Happy Birthday” oreos to the batter. He also likes Reese’s so I threw a couple of those in there and some caramel hershey kisses. They took a little longer to bake than your estimate, but turned out GREAT! Your recipes are making me a little bit of a celebrity with the girls my husband coaches 🙂

    1. Cally, your candied up version of these brownie cupcakes sounds amazing! I love everything you added to them. No wonder they were a hit. Let me know any treats you try out! I love hearing about it.

  4. I made these and they were absolutely delicious.. but I ended up with way too much frosting… I even piped quite a bit on the cupcakes.. oh well.. more frosting for me!

  5. For the frosting, could i use whipping cream instead of heavy cream? Thanks!

  6. This recipe is awesome! Just made one batch, they were so fudgy and tasty. Will definitely make this recipe again for my in-laws’. Thank you so much Sally!

  7. So… I officially have my new favorite cupcake! My sister baked them for a party a few days ago, and they were the best cupcakes I’ve ever had!

  8. Theresa Brundage says:

    I borrowed your peanut butter frosting recipe to go with my own fudge brownies. I may or may not have eaten the last 1/2 cup straight from the bowl. I now intend to work my way through every peanut butter related recipe on this page. Thanks for giving me a goal to reach for!

  9. Hello Sally..the recipe looks delicious…can you tell me what is a ‘heavy cream’ that u use for the frosting?

    1. US heavy cream is basically double cream – as it is called in other places around the world

  10. Can the brownie cupcakes be made in mini form, made ahead and frozen?

  11. Hi Sally! I tried your cupcakes they were amazing! I just wanted to know that if some day i am short of butter or its not available can i use oil and if yes that what about quantity?

  12. Hi Sally!

    These look amazing. I was just wondering what type of coco powder you used? Sweetened or unsweetened?


    1. unsweetened– sorry about that!

  13. OMG Sally, this peanut butter frosting is heaven!!! And it was so perfect with the brownie! My boyfriend said that it should be made into a cake 😉

  14. Kelley Johnson says:

    I made this frosting out of an intense craving for sweets two weeks ago. So incredibly good – I honestly think it may be your best one! So fluffy and not too sweet. Honestly, addicting.
    I was originally going to make some of those “No Pudge” Fudge brownies (it’s a low cal option to brownie box mix – all you add is greek yogurt!) but once I made them they were just begging for a frosting! lol I loved that it was a large portion of frosting. I let it set in the fridge overnight so that I could cut them into heaping squares to take to work the next day. Everyone at work was so enamored, I sent out the link to the recipe in several emails!

  15. I have been drooling over these cupcakes for about a month now anf i am about to make them. I was just wondering if it would be ok if i used salted butter and omited the afditional salt….. Looking forward to hearing back from you!!!

    1. Heather, that would be just fine. Enjoy!

  16. I’m thinking of using this frosting recipe for a 9-inch double layer you think there is enough it?

    Seems like a great recipe based on the reviews!!

    1. I would double the frosting recipe.

  17. Amanda Adams says:

    Hi! Can this recipe be made into a cake? Thanks! 🙂

  18. I would love to try this peanut butter frosting with your chewy fudge brownies with crushed peanut butter cups on top!…. Yummy!

  19. pepper sage- A Dash of Pepper says:

    I CANNOT stop eating the frosting! A-okay!!!! I am also a peanut butter freak!

  20. hi!! I love your website and alllll of your recipes! So hard to choose so just have to make them all 🙂 
    I just made these and I had to cook them for 8 min longer than you said … And only got 8 out of the recipe and that was really scraping the edges of my bowl … I hope they aren’t over baked (I don’t eat chocolate lol) – but could I have done something wrong? I checked them at 9’minutes and they were raw in the center … 

  21. Hi Sally, Made a vegan version of these for friends and now they want more. Just a quick question as so many people want to try them if I was to make mini cupcakes how long would you need to bake them for?

    1. For mini, I’d say about 10 minutes or so.

  22. Hi Sally, Could you please tell me the flour quantity in grams ? Thank you 🙂

    1. About 83 grams

  23. Stephany Eddy says:

    I’m in love!!! So simple to make and so yummy; I did post a picture on IG.

    Has anybody tried the Marshallow Frosting with these?

  24. Hi! Can u use while milk instead of heavy cream?

    1. I mean whole milk

    2. That would be OK for the frosting, yes.

  25. Hey Sally,

    Can I sub coconut milk for the heavy cream? Would I stick with the same measurement as the cream or make adjustments?

    Thank you for all the great recipes!!

  26. Hi Sally. Can I just double or triple the recipe for more? I plan to make them for a party this weekend. Thanks in advance.

  27. Hi Sally,
    I baked them for 10 min and they were raw in the center and put them back in for another 2 min, took them out and seemed underbaked! I pulled them out of the oven in hopes they would bake in the pan!! Waited abt 8-9 min and stuck toothpick in center…still not good and then put them back in the oven for 2 min…finally moist crumbs!! Possible your baking time was off?? I got 9 cupcakes!! Please let me know!! I bake all of your recipes and first time this happened!! Nervous they may be dry:(

  28. Hi Sally!

    I just wanted to say these cupcakes are absolutely amazing. I ended up getting 9 from the recipe and I’ve already had to remake them 3 times! A to finish the icing and B because they are just so darn delicous. I love cooking but have always hated baking. This recipe has made me feel like “even I can make cupcakes”
    Thank you!

    1. This comment made me so happy! I’m thrilled to hear that you enjoyed baking!!

  29. My son made these last night. He did everything on his own and only asked me a couple of questions so I cannot attest to whether he followed the recipe exactly. He is 15 and enjoys baking, so he probably did follow it to a T. However, the cupcakes didn’t come out great. We got 9 out of the batch which we expected based on comments. We baked for 8 only minutes because our oven runs hot. They came out dry and didn’t really taste like a brownie or a cupcake. Not sure where we may have gone wrong.
    But the frosting!! OMG we were eating it right out of the bowl. We have a lot leftover and plan to make something else to slather it on :-).
    We will try another chocolate cupcake and hopefully have better success. Thanks for all of the great recipes.

  30. I had the same problem as others regarding the baking time. I had to keep them in longer because they were completely raw in the middle. They were very dry and not sweet at all. Almost bitter. I actually checked the recipe again to make sure I didn’t miss some sugar. Like another poster commented, they didn’t taste like brownies or cupcakes. Nobody would eat them. They will be thrown away. A complete waste of time and ingredients.

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