Slamming-Rich Sheet Brownies
1 1/4 cups walnuts
8 ounces bittersweet or semisweet chocolate, coarsely chopped
1 cup unsalted butter, cut into chunks
1 1/4 cups all-purpose flour
2/3 cup unsweetened cocoa powder
1 1/2 teaspoons baking powder
1/4 teaspoon salt
2 cups sugar
2 teaspoons vanilla extract
In a bowl, stir together the flour, cocoa powder, espresso powder, baking powder, and salt. Set aside. In a large bowl, using a wire whisk or an electric mixer on high speed, beat the eggs until light pale yellow. Add the sugar and vanilla and heat until well combined. Stir in the melted chocolate mixture and the flour mixture. Add ¾ cup of the walnuts and stir to distribute evenly. Spread the mixture in the prepared baking pan. Finely chop the remaining nuts and sprinkle them evenly over the top.
Bake just until barely set and a toothpick inserted into the center of the brownies comes out with crumbs clinging to it, 25-30 minutes. Let cool completely in the pan on a wire rack. Invert the pan onto the rack,, lift off the pan, and peel off the foil. Transfer to a cutting board and cut into 2 ½-inch squares. Store in an airtight container for up to 2 days.
Makes 24 brownies