These Small Batch Peanut Butter Brownie Bars are a chocolate and peanut butter lover's dream! They have a small batch brownie base, topped with a smooth peanut butter filling layer, and are finished with a smooth chocolate topping.
Table of contents
Peanut Butter Brownie Bars
Hi hi! Just popping in to share this recipe with you for Peanut Butter Brownie Bars! These have been floating around on my recipe to-do list for a really long time now, and I finally got around to making them to share with you. I kept them small batch because I am loving on the little recipes these days, and I know you are too. I'm sorry I didn't do it sooner because they are just SO GOOD. But we are here now, and I think you'll forgive me quickly once you make them.
Components of Peanut Butter Brownie Bars
These are super easy, with a few components, but you can sort of mix and match them too if you like.
- Small Batch Brownie - The base of these bars is a small batch brownie. I kept it pretty thin and fudgy to form the base - if you wanted to only make this as a small batch brownie, you could use a slightly smaller pan. The brownie is baked up then left to cool for a wee bit before the topping goes on
- Peanut Butter Filling - This is heavy on the peanut butter. Butter, Peanut Butter, Powdered sugar, vanilla, and salt are mixed together, then a little bit of cream is added just to bring the whole thing together into a soft, peanut buttery play doh like situation. This gets put on top of the brownie base and smoothed down.
- Chocolate Topping: I used my go-to here, dark chocolate melted with a little neutral oil. This gives a super smooth chocolate topping, which won't crack everywhere when you go to cut it.
The benefits of small batch baking - making brownies in a loaf pan
I know I'm not the only one sharing more small batch recipes on the internet - but they are definitely more popular as we approach a whole year inside. I love them for a few reasons. The first is that they are super fun to develop. There is something so satisfying about making a tiny sheet cake or a little wee pan of brownies. I love the challenge of working out how to scale down a recipe and make it still work. Recipes are often easy to double but can be tricky to halve, so small batch makes sense as you can easily double a recipe if you need more.
It is not uncommon for me to test something upwards of 10 times before it goes anywhere near the internet. I've been trying to get better at spreading out the tests so we can get through what I make / I can give it away to friends without totally bombarding them with boxes of baking (nobody has complained yet so I think I'm good), but small batch also means that I go through less ingredients in the testing process! I often will halve a recipe for testing to get leavening right etc and recently I've started just leaving them as a half recipe. You seem to love them as much as I do, so keep an eye out for a whole bunch of small batch recipes coming your way soonish!
Can this recipe be doubled?
It sure can. The best part about making things in a loaf pan, is that you can very easily double them and bake them in an 8"x8" (20cm) square pan. These Peanut Butter Brownie Bars are no exception. They keep great in the fridge so doubling them will work well. Start checking the brownie base after about 20 minutes to see if it is done.
FAQ for Peanut Butter Brownie Bars
I use a 9"x5" (23cmx13cm) loaf pan. These are the 'larger' loaf pans (as opposed to the smaller 1lb capacity pans). I tested this in both this pan from USA pan, or also this enamel loaf pan is a similar size and works well. If you have a ⅛ size sheet pan, that would work great too.
I used Smooth peanut butter from Fix and Fogg, which is a NZ company who recently opened in the US too and they make the BEST peanut butter. It is more on the 'natural' side so just make sure you give what you are using a really good mix before you add it in, and don't use anything that separates out really badly. The creamy stuff from the store works great here too! You could probably actually use crunchy too and you would get a crunchy filling.... I may need to test this because it sounds so good.
These need to be kept in the fridge. The filling doesn't set totally hard and the oil in the topping lowers the melting point of the chocolate, so keep them cold!
I haven't personally tested it, but I think that a cup for cup gluten free flour sub (Bob's Red Mill makes a good one), would work great in the brownie base. The rest of the components are already GF so this one would be easy to do!
Make sure your knife is hot, and wipe between cuts. Some of the chocolate might drag down onto the filling, but don't worry - you're fine. It will still taste great.
I just used a single piece of parchment paper for lining my loaf pan and didn't worry about lining the short ends. However, I have total faith in my non-stick loaf pan, so if you are worried, line it with two pieces of paper so all sides are covered.
Yep! The bars keep super well in the fridge, so you can make these a couple of days ahead if needed. The brownie layer can also be made in advance and stored in an airtight container until ready to use.
I always use Heilala Vanilla in everything - the paste is my absolute favourite. You can use the code CLOUDY20 on their site for a discount if you like!
For more small batch baking recipes, check out:
Made this recipe and love it?
I would LOVE for you to leave me a review below to let me know how you liked it! Make sure to tag me on Instagram if you make it!
Why is this recipe in grams?
I post my recipes in grams as it is the most accurate way to bake. Cups are not only inaccurate but they vary in volume worldwide. There is no way for me to provide one cup measure that works for everyone. Posting in weight fixes this issue. If you would like the recipe in cups you are welcome to convert it yourself via google. Please do not ask me to do it for you as I am not comfortable providing a recipe using a method that I have not tested. Baking with a scale is easy, accurate, and makes cleanup super simple. Here is the scale that I use if you would like a recommendation! Here's to accurate baking!
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Peanut Butter Brownie Bars
- Prep Time: 30 minutes
- Cook Time: 30 minutes
- Total Time: 2 hours
- Yield: 12 servings 1x
- Category: Brownie Bars
- Method: Baking
- Cuisine: American
Description
These Small Batch Peanut Butter Brownie Bars are a chocolate and peanut butter lover's dream! They have a small batch brownie base, topped with a smooth peanut butter filling layer, and are finished with a smooth chocolate topping.
Ingredients
Brownie Base
- 60g dark chocolate, chopped
- 40g unsalted butter, cold from the fridge is fine
- 10g dutch process or regular cocoa, sifted if lumpy
- 1 large egg, at room temperature
- 30g neutral oil (such as sunflower, canola or grapeseed)
- 65g granulated sugar
- 25g light or dark brown sugar
- ¼ tsp vanilla extract or vanilla bean paste
- 30g all-purpose flour
- ¼ tsp kosher salt
Peanut Butter Filling
- 55g unsalted butter, at room temperature
- 130g smooth peanut butter
- 170g powdered sugar, sifted
- ¼ tsp vanilla bean paste or extract
- ¼ tsp kosher salt (plus more to taste if needed - add more if your PB is unsalted)
- 2 Tbsp heavy cream, plus more if needed (see notes)
Chocolate Topping
- 100g chopped dark chocolate
- 18g neutral oil
Instructions
CHOCOLATE BROWNIE BASE
- Preheat the oven to 350°f / 180°c. Grease and line a 9"x5" loaf pan (see FAQ for the exact one I used), leaving the parchment paper extending over the sides to help remove later. If you are worried about it sticking, use two pieces so all edges of the pan are covered with parchment. Secure with binder clips if desired.
- In a small heatproof bowl over a double boiler (make sure the water does not touch the bowl), or in a heatproof bowl in the microwave, melt together the chocolate and butter. I used the microwave and did it in 15 second increments, stirring after each. Mix until the chocolate is melted and the butter is incorporated. Remove from the heat and add the cocoa, and mix well to combine.
- In a medium bowl, combine the egg, oil, granulated sugar, brown sugar, and vanilla. Whisk well until thickened and slightly lighter in colour. Add the cooled chocolate mixture and mix until incorporated.
- Add the flour and salt and mix with a rubber spatula until combined.
- Transfer to the prepared pan, and smooth out well. Bang the pan on the counter several times to get it as flat as possible. Bake for 20 to 22 minutes, until the brownie looks set. Remove from the oven and, if desired, using a second loaf pan or the bottom of a drinking glass, gently press the brownie down a little if it has puffed up. Leave to cool completely in the pan.
PEANUT BUTTER FILLING
- Place the butter, peanut butter, powdered sugar, vanilla, and salt in a medium bowl. Mix using an electric hand mixer on medium to high speed, until the mixture is incorporated - it will go crumbly and look weird, do not freak out. You can do this step in a stand mixer fitted with the paddle or whisk attachment too if you like, if your mixer bowl is small enough to work with a small batch.
- Add the cream and mix to combine, and then continue to mix until the mixture smooths out and becomes light, fluffy and spreadable. If you feel it is too firm, add extra cream a tsp at a time until it is smooth enough.
- Transfer the filling on top of the cooled brownie layer, and smooth out with an offset spatula. Once it is fairly smooth, you can continue to smooth it down by placing a piece of parchment on top of the filling and use your fingers to smooth it. Don't worry if you don't get it totally flat - it can be really hard to fit the spatula into the loaf pan.
- Once the filling is smooth, transfer to the freezer for 20 minutes to firm up, or the fridge for about 30 minutes. It doesn't need to be totally firm - it will finish chilling down with the chocolate. Do not leave in the freezer for more than 20 min or it will make it hard to evenly spread the chocolate (it is fine in the fridge).
CHOCOLATE TOPPING
- Melt together the chocolate and the oil in a small heatproof bowl in 15 seconds increments in the microwave, or over a double boiler. Mix until totally smooth.
- Remove the peanut butter brownie bars from the fridge or freezer and pour the chocolate over the top of the peanut butter filling. Tilt the pan to spread out to cover the filling evenly with the chocolate. Bang the pan a few times on the counter to make sure there are no bubbles.
- Place the pan in the fridge and leave to chill for about an hour, or until completely set.
- Use the parchment overhang to remove the bars from the pan. Cut into pieces using a sharp knife, wiping between cuts.
- Store leftovers in an airtight container in the fridge.
Notes
A note on salt and cream - the type of peanut butter that you use will determine the consistency of the filling. If you find it is still a little firm (it should be spreadable but not sloppy), add a teaspoon at a time of cream and mix to combine until you are happy with the texture. The salt you add will also depend on your peanut butter - if it has added salt you may not need to add more but if you have unsalted peanut butter or like a slightly saltier layer (I do), add a little more!
Keywords: Small Batch, Peanut Butter, Brownie Bars, Small Batch Brownies, Peanut Butter Brownie Bars
Can't wait to make these!
★★★★★
Thank you for the recipe, I love the small serving size! I didn't have the same size pan - so I used a 5 inch round spring form pan and it made the presentation really cute. Between the brownie and the pb layer the pan was full so I ended up just pouring the final chocolate layer over top after I removed the pan. I added some chopped peanuts to the top. Especially love the pb layer - I used chunky pb and it turned out very well.
★★★★★
Yay I am so so happy you loved!
I love that these are small batch 🙂
★★★★★
I went to make these and realised your brownie recipe is missing a step - there is no instruction to add the melted chocolate mix to the rest of the ingredients. Fabulous to see a recipe using F&F pb!
Hiii so sorry I fixed it!
Hi Erin! Can’t wait to make these! We’re in the middle of moving and my electric hand mixer is somewhere in transit... I’ve only got my KitchenAid or a good old hand whisk! Am I going to have a shit time with the peanut butter layer using either of those things and should I just wait until I get my hand mixer back? Thanks for your advice.
Hi! Kitchen aid will work just fine! 🙂
These were AMAZING! Worth the wait while it set.
★★★★★
Yayyyyy so happy you loved!!
Can you tell again the size of the pan since when I click the link you provided for doesn’t show the pan anymore please. Thanks
Hi, the size is written in the FAQ and also the recipe 🙂
Great recipe! I added flakey salt to the top of the chocolate layer cause I love a salty dessert and they are delicious! Love that it’s a small batch recipe! And love all your recipes everyone I have tried has come out perfectly!
★★★★★
Weee so happy that you loved! Thanks so much for the lovely review x
Just made these and they were a huge hit! My boyfriend who doesn’t like desserts even went back for seconds!
Super easy and really delicious!!
★★★★★
Yayyy I love to hear that! Mine said he wouldn't like it either and suddenly when I went to take a test batch for a friend he didn't want me to take it and decided it needed to be left at home!? hahahahhaha
This is one of the best bars I’ve ever made, period. Erin’s notes are always so excellent and everything comes out perfect even when there are three different layers!!! She makes baking these easy. Now I need to figure out if these freeze well so I can have a bite whenever I need it!
Good gracious! These bars are AMAZING! That fluffy peanut butter filling is so close to that Reese’s peanut butter cup flavor when matched with the brown and chocolate top layer that I can barely believe I made these with my own hands. I will absolutely make these again! So easy and a real taste bud show stopper! Also, thanks for another small batch winner, Erin 🙂.
★★★★★
These are INSANELY good. As in, ‘I’ve never had so many people ask me for the recipe before’ good. Stop reading the reviews and make these right now, this is your sign!!
★★★★★
Aw yayy yesss!