Prep and Baking Time: 1 hour (doesn’t include cooling)
Peanut Butter Batter:
3 tablespoons (43 grams) butter, melted
¾ cup (190 grams) smooth peanut butter
⅓ cup (45g) confectioner’s sugar
4 ounces (114g) 70-75% dark chocolate, roughly chopped
1/2 cup (115 grams or 4 ounces) butter, plus more for pan
1 cup plus 2 tablespoons (225g) granulated sugar
2 large eggs, room temp
1 teaspoon (5 ml) vanilla extract
2/3 cup (85 grams) all-purpose flour
¼ teaspoon salt (omit if using salted butter)
2 oz (57g) chocolate, chopped
Preheat the oven to 350°F (177°C) and grease an 8” or 9” square pan or line with aluminum foil or parchment paper, leaving an overhang on the sides to lift out the finished brownies (makes cutting easier!). Set aside.
Peanut Butter Batter: In a medium bowl, stir all ingredients together until smooth
Brownie batter: In a microwave-safe bowl, combine butter 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 vanilla. Add flour and fold together with a rubber spatula or wooden spoon until almost combined. Add chopped chocolate, reserving a small handful to sprinkle on top, and finish mixing just until no more flour streaks remain.
To assemble brownies, spread a thin layer of brownie batter in bottom of prepared baking pan. Dollop peanut butter batter all over in big spoonfuls, leaving gaps between spoonfuls. Drop remaining brownie batter in pan between the peanut butter batter. Use a butter knife to swirl the batters together in loose figure-8s. Sprinkle reserved chocolate on top.
Bake for 35-40 minutes.To test if brownies are done, insert toothpick into the center of the pan (avoiding the peanut butter batter and chocolate chunks as much as possible), when the toothpick comes out with moist crumbs, the brownies are done. If batter is wet, continue to check every two minutes. Remove from the oven and place on a wire rack to cool completely before cutting into squares.