These mega peanut butter swirl brownies are unapologetically rich and fudgy! This homemade brownie recipe is one of my favorites and so easy to make.
- 1 cup (16 Tbsp; 2 sticks; 230g) unsalted butter, divided
- one 4 ounce (113g) semi-sweet chocolate bar, coarsely chopped*
- 2 cups (400g) granulated sugar
- 3 large eggs, at room temperature
- 2 teaspoons pure vanilla extract, divided
- 1 cup (95g) unsweetened natural or dutch-process cocoa powder*
- 1 cup (125g) all-purpose flour (spoon & leveled)
- 1 teaspoon salt
- 1 and 1/2 cups chopped peanut butter cups
- 1 cup (250g) creamy peanut butter*
- 1/2 cup (60g) confectioners’ sugar
- Preheat the oven to 350°F (177°C) and grease a 9×13 inch pan or line with aluminum foil or parchment paper, leaving an overhang on the sides to lift the finished brownies out (makes cutting easier!). Set aside.
- Brownie batter: In a microwave-safe bowl, combine 3/4 cup butter (12 Tbsp; 1 and 1/2 sticks) and chopped chocolate. Melt in 30 second increments, whisking after each, until completely smooth. Whisk in the granulated sugar until completely combined, then whisk in the eggs and 1 teaspoon vanilla. The batter will be light brown and a little dull looking.
- Add the cocoa powder, flour, and salt. Fold it all together with a rubber spatula or wooden spoon. Batter will be very thick. Stir in chopped peanut butter cups, reserving a small handful to sprinkle on top. Set aside.
- Peanut butter swirl: Melt the remaining butter. Using a hand-held or stand mixer fitted with a paddle or whisk attachment, beat the melted butter, remaining 1 teaspoon of vanilla, the peanut butter, and confectioners’ sugar until smooth. Drop big spoonfuls of most of the chocolate batter randomly into the prepared pan– see photo above for a visual. Top with random spoonfuls of all of the peanut butter batter. Drop random spoonfuls of remaining chocolate batter over any bare spots or heavy peanut butter spots. Using a knife, swirl the batters together. The brownie batter is pretty thick, so do your best. Sprinkle with any leftover peanut butter cups.
- (See note about how to tell if brownies are done in the post above.) Bake for 30 minutes, then test the brownies with a toothpick. Insert it into the center of the pan. If it comes out with wet batter, the brownies are not done. If there are only a few moist crumbs, the brownies are done. Keep checking every 2 minutes until you have moist crumbs. My brownies take 33-36 minutes.
- Remove from the oven and place on a wire rack to cool completely before cutting into squares. Cover and store leftover brownies at room temperature for up to 1 week.
- Make Ahead Instructions: Brownies freeze well up to 3 months. Thaw overnight in the refrigerator then bring to room temperature before serving.
- Chocolate Bars: Chocolate bars are typically sold in 4 ounce bars. I suggest Ghirardelli, Baker’s brand, or Lindt. Do not use chocolate chips.
- Cocoa Powder: You can use either natural or dutch-process cocoa powder. I prefer dutch-process for a smoother flavor.
- Peanut Butter:Use a generic creamy peanut butter like Jif or Skippy. Crunchy could work too. Do not use natural, homemade, or super oily brand as the swirl will not set up properly.