Rating: 3.55 stars
423 Ratings
  • 5 star values: 95
  • 4 star values: 139
  • 3 star values: 112
  • 2 star values: 58
  • 1 star values: 19

Dollops of peanut butter filling are spooned onto brownie batter; pulling a knife back and forth through both results in a marbleized look.

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Ingredients

For the batter
For the filling

Directions

Instructions Checklist
  • Preheat oven to 325 degrees. Line a buttered 8-inch square baking pan with foil or parchment paper, allowing 2 inches to hang over sides. Butter lining (excluding overhang); set pan aside.

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  • Make batter: Put butter and chocolates in a heatproof medium bowl set over a pan of simmering water; stir until melted. Let cool slightly.

  • Whisk together flour, baking powder, and salt in a separate bowl, and set aside.

  • Whisk granulated sugar into chocolate mixture. Add eggs, and whisk until mixture is smooth. Stir in vanilla. Add flour mixture; stir until well incorporated.

  • Make filling: Stir together butter, confectioners' sugar, peanut butter, salt, and vanilla in a bowl until smooth.

  • Pour one-third of batter into prepared pan, and spread evenly with a rubber spatula. Place dollops of filling (about 1 tablespoon each) about 1 inch apart on top of batter. Drizzle remaining batter on top, and gently spread to fill pan. Place dollops of remaining filling on top.

  • With a butter knife, gently swirl filling into batter, running knife lengthwise and crosswise through layers. Bake until a cake tester inserted into brownies (avoid center and edges) comes out with a few crumbs but is not wet, about 45 minutes. Let cool slightly in pan, about 15 minutes. Lift out brownies; let cool completely on a wire rack before cutting into squares.

Cook's Notes

To swirl brownies, work quickly so that batter and filling don't set. Use two large spoons to drop dollops of filling on the first layer of batter about one inch apart. Repeat with next layer of batter and remaining filling. Drag a butter knife back and forth through the layers with the tip touching the bottom of the pan.

Reviews (25)

423 Ratings
  • 5 star values: 95
  • 4 star values: 139
  • 3 star values: 112
  • 2 star values: 58
  • 1 star values: 19
Rating: 2 stars
01/02/2014
The taste of the brownies is good but they crumbled apart on me. I had to bake them 10 minutes longer because they weren't set after I had baked them for the amount of time the recipe called for. When I tried to cut the first brownie it crumbled and I thought it was just because it was the first. But then the next and next crumbled too. I wouldn't make this recipe again.
Rating: Unrated
11/01/2013
Personally (don't listen to the others) - this was simply amazing! It was slightly more cake-like compared to a normal chewy brownie, but I preferred that! I edited the recipe a tad too - I doubled the amount of Peanut Butter on top (but I love Peanut Butter), added some milk chop chips on top of the Peanut Butter as well - because I absolutely adore chocolate! I then also added a few spoonful's of Peanut Butter into the chocolate mixture whilst it was melting. They were simply delightful!
Rating: Unrated
10/12/2013
So disgusting. Don't bother wasting your ingredients. This is not a brownie.
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Rating: Unrated
06/27/2013
It would be nice if Martha took a basic writing class before uploading any more recipes. There should have been two separate ingredient lists: one for the brownies and the other for the topping. As it is now, it is almost impossible to follow. Spend a little less energy being pretentious and a little more being CLEAR. I am sure most bakers are primarily interested in yielding positive results as opposed to reading a fancy web site.
Rating: 1 stars
06/18/2013
I wanted to add to my below review that the peanut butter filling portion of this recipe was actually quite good despite the whole brownie not being the best.
Rating: 1 stars
06/17/2013
Unfortunately, I wish I had read more of the reviews for this recipe prior to making the brownies. If you like "cakey" brownies, then this is the recipe for you because even if you cut back on the baking time, they're still cakey. This recipe is not worth the time or ingredients that are needed to make it. Furthermore, the recipe is incredibly unclear the way it's written as it pertains to what the measurements of the ingredients are specific to the batter and filling. Very disappointing...
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Rating: Unrated
03/11/2013
These brownies are chewy and soft. One of the best combo with peanut butter and chocolate, I think.
Rating: Unrated
03/05/2013
窩喔喔喔喔!
Rating: Unrated
02/16/2013
These brownies are, hands down, the BEST I EVER HAD. Anyone who's unsure of making these, just make 'em!
Rating: Unrated
02/01/2013
I was in a hurry, so I used Ghiradelli brownie mix and added the M S peanut butter swirl, had to bake an xtra few min, but it was a big hit, very moist and fudgy! cheater, I know ; )
Rating: Unrated
11/07/2012
Made this recipe for my daughter's birthday and it came out SO good! Not dry at all and the cook time was perfect. Will definitely make these again!
Rating: Unrated
08/12/2012
Wow, these brownies were a HUGE disappointment!!! I found them to be very cakey and dry, and I did NOT overbake them. They were done at 35 mins. I even used Ghiradelli chocolate and that didn't make any difference. I tried two and I honestly am considering discarding them b/c they are not worth the calories! This recipe is going in the trash. Sorry, Martha.
Rating: Unrated
08/10/2012
I really did not like this recipe, as others said- way too rich and too cakey. I prefer a gooey moist brownie. bleh.
Rating: Unrated
08/01/2010
I found these brownies to be very cakey, which is not my preference. If you prefer fudgy brownies, I would recommend using a different recipe for the batter.
Rating: Unrated
05/14/2010
These brownies are great- although the time is way too high. As another person commented, I would check the brownies at 35 minutes. They will probably be done. Unfortunately mine were a little charred by the full 45 minutes. Still yummy though with all of the corners cut off!
Rating: Unrated
12/16/2009
Does anyone know if this was a recipe in Martha's magazine from the around roughly December 2005? I've been looking for the recipe for ages!
Rating: Unrated
07/26/2009
I was too lazy to make the brownies...so I used a box mix but made the filling as directed above and now every time I'm invited to the neighbor's for Sunday night dinner - if I don't have these brownies with me...they won't let me in!
Rating: Unrated
05/24/2009
I made this exactly per recipe and it was delicious! My baking time was slightly reduced though, only 35-40 mins. Will definately make again.
Rating: Unrated
05/21/2009
They were very good, but I just melted chocolate chips for the chocolate and it came out good. Had to increase the baking time though.
Rating: Unrated
11/18/2008
I made this recipe out of "Martha Stewart's Cookies" cookbook. In that recipe, the 2 tsp of vanilla is, indeed, in with the batter part of the recipe while the 1/2 tsp is in with the filling. This recipe is rich, but delicious! My family was raving about these brownies. I am now online to send the recipe to a friend!
Rating: Unrated
08/26/2008
Something seemed to clash, the taste in this brownie. The chocolate made it to sweet or something. Next time i might use 3 ounces semisweet and 3 ounces milk chocolate...I also had to add 5-10 minutes onto the baking time.
Rating: Unrated
02/05/2008
2 tsp. vanilla for the batter, and 1/2 tsp. for the filling
Rating: Unrated
02/05/2008
re: vanilla issue, I would assume 2 tsp. vanilla extract for the batter,
Rating: Unrated
01/11/2008
Need clarification. How much vanilla in batter? How much vanilla in filling?
Rating: Unrated
12/25/2007
The brownies were very good. They were VERY rich though and needed a bit longer in the oven about 5-10 minutes longer. If you don't mind having very rich brownies, they are perfect.