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Peanut-Butter Swirl Brownies

Dollops of peanut butter filling are spooned onto brownie batter; pulling a knife back and forth through both results in a marbleized look.
Martha Stewart Living Special Issues, 2005
  • Yield Makes 9 large or 16 small squares
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Ingredients

  • FOR THE BATTER

    • 8 tablespoons (1 stick) unsalted butter, cut into small pieces, plus more for pan
    • 2 ounces good-quality unsweetened chocolate, coarsely chopped
    • 4 ounces good-quality semisweet chocolate, coarsely chopped
    • 2/3 cup all-purpose flour
    • 1/2 teaspoon baking powder
    • 1/4 teaspoon salt
    • 3/4 cup granulated sugar
    • 3 large eggs
    • 2 teaspoons pure vanilla extract
  • FOR THE FILLING

    • 4 tablespoons unsalted butter, melted
    • 1/2 cup confectioners' sugar
    • 3/4 cup smooth peanut butter
    • 1/4 teaspoon salt
    • 1/2 teaspoon pure vanilla extract

Directions

  1. Preheat oven to 325 degrees. Butter an 8-inch square baking pan and line with parchment, allowing a 2-inch overhang. Butter lining (not overhang).

  2. 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 bowl.

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

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

  5. Pour one-third of batter into prepared pan; spread evenly with a rubber spatula. Drop dollops of peanut butter filling (about 1 tablespoon each) on top of batter, spacing about 1 inch apart. Drizzle remaining batter on top, and gently spread to fill pan. Drop dollops of remaining filling on top. Gently swirl peanut butter filling into batter with a butter knife, running the knife lengthwise and crosswise through layers.

  6. 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; let cool completely on a wire rack before cutting into squares. Brownies can be stored in an airtight container at room temperature up to 3 days.

Cook's Note

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.

Recipe Reviews

Reviews (20)

  • PIE Lover
    11 Mar, 2013

    These brownies are chewy and soft. One of the best combo with peanut butter and chocolate, I think.

  • Rebecca Su
    5 Mar, 2013

    窩喔喔喔喔ï¼

  • Rachel g
    16 Feb, 2013

    These brownies are, hands down, the BEST I EVER HAD. Anyone who's unsure of making these, just make 'em!

  • momof4boyz
    1 Feb, 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 ; )

  • Happy_Birthday_Dr_Seuss
    31 Jan, 2013

    Peanut-Butter Swirl Brownies
    Russell's Thursday Dinner
    Nutritious and Delicious!

  • Krista Tracy
    7 Nov, 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!

  • lisamaria
    12 Aug, 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.

  • mwilly
    10 Aug, 2012

    I really did not like this recipe, as others said- way too rich and too cakey. I prefer a gooey moist brownie. bleh.

  • ChristineSF
    1 Aug, 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.

  • acase
    14 May, 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!

  • cheftash
    16 Dec, 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!

  • ozburnmso
    26 Jul, 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!

  • Shorty01
    24 May, 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.

  • rose20
    21 May, 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.

  • kell_rae
    18 Nov, 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!

  • lovesbaking
    26 Aug, 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.

  • baileyboy
    5 Feb, 2008

    2 tsp. vanilla for the batter, and 1/2 tsp. for the filling

  • baileyboy
    5 Feb, 2008

    re: vanilla issue, I would assume 2 tsp. vanilla extract for the batter,

  • janetrichards
    11 Jan, 2008

    Need clarification. How much vanilla in batter? How much vanilla in filling?

  • robyn07
    25 Dec, 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.