Peanut Butter Brownies

Super chewy, rich brownies marbled with a creamy peanut butter swirl. Chocolate and peanut butter is a winning flavour combination!

several brownies

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Recipe updated November 2020 (to make them even more chewy!)

Yup, I’ve taken my original Chewy Homemade Brownies recipe and made them next-level good by adding creamy swirls of peanut butter!

After nailing my ideal brownie recipe, I realised I could enhance the recipe by adding in other flavours (such as my Banoffee Brownies and Nutella Brownies). Let’s face it, chocolate and peanut butter together seemed like a great place to start.

I love baking brownies as they are genuinely quick to mix together. They’re great if you need something delicious in a hurry!

plate of brownies showing peanut butter swirl pattern

Easy Peanut Butter Brownies recipe

Incorporating the peanut butter flavour couldn’t be easier. I simply added melted butter to the peanut butter to loosen the peanut butter. This makes it easier to swirl through the brownie mix!

I love how pretty the brownie tops look once baked. Plus they still have their shiny crackled tops!

view from above of plate of brownies

The Best Chewy Peanut Butter Brownies

As I talked about in my original brownie recipe, the texture of these brownies took several attempts to get just right. My recipe contains no raising agent, less flour and some light brown sugar to make them extra moist. Plus, they contain fewer eggs and more butter. This all results in a denser, chewier brownie!

My Banoffee Brownies recipe has a slightly different texture which is less chewy but super moist thanks to the bananas in the brownie mix.

bite taken out of peanut butter brownie

Simple peanut butter brownies with no mixer needed

One of my favourite things about brownies is how they can be whipped up quickly without the need for a mixer. So if you’re looking for a quick tray-bake recipe and have some bowls and a wooden spoon, you’re good to go!

You just need a simple traybake pan, measuring around 12″ by 9″. This is the size I tend to use for all my traybake recipes (my No-Bake Healthy Chewy Snack Bars recipe can be doubled to fit into this size pan!). I simply line mine with baking paper, or if I use foil instead, I spray it lightly with non-stick cake pan spray.

The most difficult part is waiting for them to cool once baked. Try to wait until they’ve cooled completely before cutting into pieces as they need to set before slicing!

chocolate peanut butter brownies

So to summarise, these brownies are deliciously chewy and rich, plus genuinely easy to make with minimal washing up.

I’m confident that if you like chocolate and you like peanut butter, you will find it hard to resist eating just one of these.

If you try this recipe I’d love to see! You can show me by tagging me @bakerjoblog or using #bakerjoblog!

close up of side view of a peanut butter brownie

Other traybakes to try:

other chocolate recipes to try:

chocolate peanut butter brownies

Peanut Butter Brownies

Super chewy, rich brownies marbled with a creamy peanut butter swirl. Chocolate and peanut butter is a winning flavour combination!
5 from 1 vote
Prep Time 25 mins
Cook Time 30 mins
Course Snack
Servings 24 small brownies


  • 12" x 9" traybake tin


Brownie mixture

  • 100 g plain flour
  • 60 g cocoa powder
  • 1/2 tsp salt level
  • 250 g caster sugar
  • 50 g light brown sugar
  • 200 g butter cubed
  • 180 g dark chocolate chopped
  • 1 tsp vanilla extract
  • 3 medium eggs room temperature
  • 160 g chocolate chips milk or dark (sweet or semi-sweet)

Peanut butter swirl

  • 240 g smooth peanut butter
  • 40 g melted butter


  • Preheat your oven to 170°C/150°C fan. Grease a 12″ x 9″ traybake tin with butter or non-stick spray, line with foil/baking/parchment paper. If using foil, spray it again with non-stick spray once lined. 
  • To a medium bowl add the flour, cocoa powder and salt. Whisk to combine and set aside.
  • To a large bowl add the caster and light brown sugar. Set aside.
  • In a medium microwave-safe bowl, add the chopped dark chocolate and cubed butter. Heat in microwave in 20-second increments, stirring in between until melted and no lumps of chocolate remain.
  • Pour this melted chocolate-butter mixture into the large bowl containing both sugars. whisk together until combined, about 30 seconds.
  • Add the vanilla extract and whisk to combine.
  • Now add the eggs, one by one, whisking thoroughly between each addition to ensure they’re fully incorporated. With each addition of egg, you’ll notice the batter feels thicker and more difficult to whisk, so you may need to scrape from the bottom and fold together in between whisking. 
  • Put your whisk aside and use a spatula/wooden spoon from this point. Add half the dry ingredients to this large bowl and fold gently until just incorporated. Repeat with the remaining half of dry ingredients. This will also feel a bit tricky to mix together at first but stick with it! Make sure no pockets of flour remain and try not to over-mix.
  • Add the chocolate chips and fold together until spread evenly through your brownie batter.
  • In a small bowl mix the peanut butter and melted butter together until incorporated and smooth.
  • Pour 2/3 of the brownie batter into your prepared traybake tin. It will be thick so you will need to spread it evenly into all corners of your traybake tin, and level it as best you can with your spatula so that it bakes evenly.
  • Using a spoon, drop spoonfuls of the peanut butter mixture on top of the brownie mixture in the tin, then drop spoonfuls of the remaining brownie mixture between the peanut butter. Using a butter knife swirl up and down through the mixture to create a marbled effect.
  • Place the traybake tin onto the middle shelf of your preheated oven for between 25-30 mins. Mine took 30 minutes. Test from 25 minutes by inserting a cake skewer or cocktail stick into several areas of the brownie – there should be some moist crumbs on the skewer/stick. If it comes out clean, the brownies are over-baked. If it contains wet mixture, it is under-baked so place back in the oven for 2 more minutes before testing again. 
  • Once baked, place on a wire cooling rack to cool completely. Try to resist the urge to remove them or cut into them before they’re cool as they need time to set.
  • Brownies will keep well in an airtight container at room temperature for around 5 days. 
    chocolate peanut butter brownies


If you’ve tried this recipe, tag @bakerjoblog on Instagram, Facebook, Pinterest or Twitter and/or use #bakerjoblog!
Keyword brownies, chocolate, peanut butter


  1. 16th December 2020 / 2:55 am

    5 stars
    I love peanut butter brownies. Love that this is super easy to do. Thanks for this!

    • Jo
      16th December 2020 / 11:39 pm

      No problem, I hope you enjoy them!

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