Incredibly gooey and delicious, these brownies with peanut butter swirl are irresistible and the combination of chocolate and peanuts takes these fudgy bars up a million notches! They keep for days and can be frozen. And I added a variation with almond butter and cocoa nibs.
The combination of peanut butter and chocolate never ceases to amaze me for how delicious it is.
I took them to the office, and they were an instant hit!
People raved about them, and at one point, I had a shadow following me around the office asking for an encore, not the recipe mind you, just another batch 'whenever you feel like baking them again'.
And they are as easy to make as they look. There is no need for fancy equipment or complicated techniques. Just two simple mixtures baked together until gooey.
How to make peanut butter brownies
- Make the brownie base. This recipe is one bowl, which means you melt the chocolate and butter and add the rest of the ingredients to the same bowl.
- Spread the batter in the prepared pan.
Peanut butter swirl
- Put dollops over the brownie base.
- Marble or swirl using the tip of a knife (second image below). Do this lightly for better results.
- Bake until dry, but the center is still jiggly.
- Let cool and cut. I like to eat them the next day. I find the flavor is much better.
Vintage Kitchen tip: these brownies are extra fudgy, so consider that they will need refrigeration time to set properly. I recommend eating them somewhat cold for better consistency.
Type of pan to use
I don't normally specify a certain pan to make brownies, but in this case, it's necessary.
I always use metal pans, the ones you see in the images.
But a few readers commented that the brownies never fully baked and that they were fudgy not in a good way, almost raw. It turns out they use a glass pan.
I tested the recipe again in said pan, and it turns out that the middle never quite sets. It remains extremely soft and underbaked.
So use a metal pan, NOT a glass pan.
Kitchen notes
- Organization: read the recipe first and make sure you have ingredients at the right temperatures, equipment needed, and enough workspace. This will make the process so much easier.
- Baking time: keep in mind that all ovens and pans are different, even if they look the same or very similar. The baking time in my recipes is as accurate as it can be, but it might take you more or less time. Use a thermometer inside the oven (like the OXO oven thermometer) to check that the temperature is right. I recommend you keep track of how your oven works and what tiny details you might need to adjust.
- Peanut butter: I always make them with commercial peanut butter, the traditional type, but they do work with natural peanut butter, too.
- Swirl: when marbling or swirling the peanut butter mixture, do so lightly. We want two distinctive batters to appear.
- Pan size: it's very important to ensure a fudgy and gooey brownie that bakes well.
- Baking: brownies, in my opinion, should be slightly underbaked to ensure that soft and gooey bite we all love. That means the center should still jiggle when removed from the oven.
- Storing: I suggest eating brownies the next day that they are baked. The flavor is deeper and the texture has time to settle. These can be frozen, well wrapped, for a month at least.
Almond butter brownies variation
I have made this recipe with almond butter and nibs (they are fantastic and a tad healthier) many times by substituting the following:
- Almond butter for the peanut butter, same amount.
- Cocoa nibs for the cocoa powder: finely grind 2 tablespoons of cocoa nibs and substitute them for the cocoa powder.
- Coconut sugar: I use it instead of brown sugar.
The rest of the recipe remains the same.
Related recipes you might like:
One last thing
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Fudgy Peanut Butter Brownies
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Ingredients
For the brownie base:
- ¾ cup 4.5oz semi-sweet chocolate, coarsely chopped
- ¾ cup unsalted butter
- ¾ cup granulated sugar
- ¾ cup dark brown sugar
- 3 eggs, at room temperature
- 2 teaspoons vanilla extract
- Drops of almond extract
- 1 cup all-purpose flour
- 1 ½ tablespoons unsweetened cocoa powder
For the peanut butter swirl:
- ⅔ cup peanut butter
- 5 tablespoons powdered sugar
- ½ teaspoon vanilla, optional
- 2 or 3 tablespoons cream, double, whipping or heavy
Instructions
For the brownie base:
- Preheat the oven to 350ºF (180ºC).
- Butter or spray an 8-inch square metal pan (don't use a glass pan). Line it with a piece of parchment paper covering the bottom and two sides. Two sides will remain unlined.
- Melt the chocolate and butter together in a large glass bowl. I do it in the microwave oven, stirring every 10 seconds, until the chocolate is smooth. You can also do it over a pot of boiling water, careful the bottom doesn’t touch the water, stirring until it's melted.
- Mix both sugars into the chocolate.
- Add the eggs, vanilla, almond extract if using, and cocoa. Mix until well combined.
- Add the flour in 2 parts and mix carefully, but don't overmix.
- Spread the batter into the prepared pan.
For the peanut butter swirl:
- In a medium bowl, mix together peanut butter, powdered sugar, vanilla, and cream. Make sure no lumps remain.
- Drop spoonfuls on top of the brownie base, then swirl lightly with a knife, ensuring you leave whole chunks of peanut butter mix intact. Otherwise, it all blends together, and it won't have the same effect.
- Bake for 25-30 minutes, depending on the pan you use, until a cake tester or toothpick comes out with very fudgy crumbs, the top looks dry, and the center still jiggles. It's important not to overbake them.
- Let cool on a wire rack completely.
- I find that they are better the next day. I keep them wrapped in plastic.
- They can be frozen, well wrapped.
Notes
Adapted from Good Housekeeping Cookbook
Jessi Fisher says
These tasted delicious, but when I used an all natural peanut butter instead of regular grocery store, peanut butter, the consistency of the peanut butter mixture became very thick and extremely difficult to swirl into the brownie batter. Quite disappointed. Perhaps because there was no palm oil in the peanut butter, it wasn't liquid enough to swirl?
Paula Montenegro says
Hi Jessi, natural and commercial peanut butters can differ quite a lot in texture and fluidness, and it affects consistency.
Kelli says
These are quite literally the best peanut butter brownies I've ever made and I bake A LOT. I will keep coming back to this recipe. These were devoured within hours of baking.
Liz says
I am using a 9 x 9 inch glass baking dish. I have baked it for 30 min. And it is still very jiggly in the center. I tried baking about 10 more min and it still seems very gooey in the middle. Has anyone else had this issue?
Paula Montenegro says
Hi Liz! Brownies in a glass pan take longer to bake. How much is it jiggling? They will firm up a lot when they cool down. If you insert a toothpick it should come out with moist, almost wet crumbs but not runny.
Lisa says
Can you bake these in a muffin tin? What would be the bake time?
Paula Montenegro says
Hi Lisa! They're very fudgy and they might be difficult to take out of the pan without breaking them. If you do try it anyway, let them cool down, run a flat knife around the edges to loosen them and see if you can take out one. Brownies are always better the next day when the ingredients have solidified better.
Randy says
Can you use semi sweet chocolate chips if you don't have anything else?
Paula Montenegro says
Hi Randy, you can substitute them, but the brownies will be lighter in color and sweeter.
Jeff says
Sorry for a substitution question, but do you think butter could be used instead of cream for the peanut butter? Thank you. Eager to try this.
Paula Montenegro says
Hi Jeff! The cream loosens up the peanut butter mixture, so if using butter instead, add half the amount first and see how it goes. Add more if necessary. It should be creamy enough to lightly swirl, but don't let it thin too much. Hope this helps.
Lyn says
Hello-for the chocolate-can we use chocolate (baking) chips? Thanks.
Paula Montenegro says
Yes Lyn, you can.
Marlene Gris says
Hi Paula,
Do you think that your Peanut Butter Swirl Brownie recipe with Dulce de Leche replacing the peanut butter mixture would work? I have a jar of Cachafaz Dulce de Leche and thought I might try it. Do you think it would burn during baking?
Marlene
Paula Montenegro says
Hi Marlene! It should work. The top does caramelize but it shouldn't burn. There is a recipe for dulce de leche brownies with a swirl and no issues at all.
Marlene Gris says
Your Peanut Butter Swirl Brownies are "to die for". They actually beat out another Peanut butter brownie recipe that I made at the same time as judged by my very critical brownie loving son.
Your kitchen notes are always very helpful.
Renee says
Hi - If I only have an 8"x8" pan would you recommend using slightly less batter in the pan and making mini's out of the rest? Or increase the bake time by a few minutes? Thanks
Paula Montenegro says
Hi Renee! Use all the batter in the 8-inch pan, it'll be fine. The baking time will not differ greatly.