Store brownies in an airtight container at room temperature for up to 3 days.
Recipe information
Yield
Makes 9 large or 16 small squares
Ingredients
For the Batter
For the Filling
Preparation
Step 1
Preheat the oven to 325°F. Line a buttered 8-inch-square baking pan with foil or parchment paper, allowing 2 inches to hang over the sides. Butter the lining (excluding the overhang); set the pan aside.
Step 2
Make the batter: Put the butter and chocolates in a heatproof medium bowl set over a pan of simmering water; stir until melted. Let cool slightly.
Step 3
Whisk together the flour, baking powder, and salt in a separate bowl, and set aside.
Step 4
Whisk the granulated sugar into the chocolate mixture. Add the eggs, and whisk until the mixture is smooth. Stir in the vanilla. Add the flour mixture; stir until well incorporated.
Step 5
Make the filling: Stir together the butter, confectioners’ sugar, peanut butter, salt, and vanilla in a bowl until smooth.
Step 6
Pour one-third of the batter into the prepared pan, and spread evenly with a rubber spatula. Place dollops of filling (about 1 tablespoon each) about 1 inch apart on top of the batter. Drizzle the remaining batter on top, and gently spread to fill the pan. Place dollops of the remaining filling on top.
Step 7
With a butter knife, gently swirl the filling into the batter, running the knife lengthwise and crosswise through the layers. Bake until a cake tester inserted into the brownies (avoid center and edges) comes out with a few crumbs but is not wet, about 45 minutes. Let cool slightly in the pan, about 15 minutes. Lift out the brownies; let cool completely on a wire rack before cutting into squares.
