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


Comments are closed.

  1. 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 … 

  2. 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.

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

    1. About 83 grams

  4. 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?

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

    1. I mean whole milk

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

  6. 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!!

  7. 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.

  8. 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:(

  9. 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!!

  10. 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.

  11. 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.

  12. Pretty easy and good. The icing is beyond amazing. One complaint is that the cake is really dense and small. These cupcakes are so rich and you only want to eat one at a time.

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I’m Sally, a cookbook author, photographer, and blogger. My goal is to give you the confidence and knowledge to cook and bake from scratch while providing quality recipes and plenty of pictures. Grab a cookie, take a seat, and have fun exploring! more about Sally