Instructions

• Preheat oven to 350°F. Line an 8x11-inch baking tray with foil, leaving some overhang on two opposite sides to use for lifting the bars out later.
• In a large, heavy pan over low heat, gently melt 10 tablespoons unsalted butter, stirring until melted. Remove the pan from the heat.
• Add 2 cups light brown sugar to the melted butter and stir until combined. Let the mixture cool for about 1 minute.
• In a small bowl, beat 3 eggs until blended. Stir the beaten eggs and 1 teaspoon pure vanilla extract into the butter-sugar mixture until combined.
• Sift 3 cups all-purpose flour, 1 teaspoon baking powder, and a large pinch salt together, then sift the mixture over the wet ingredients. Stir only until the dry ingredients are just incorporated—do not overmix.
• Fold in ½ cup chopped walnuts and 1 cup semisweet chocolate chunks until evenly distributed.
• Pour the batter into the prepared pan and spread it into an even layer.
• Bake for 25 minutes, or until the top is just firm (a toothpick inserted near the center should come out with moist crumbs, not wet batter).
• Cool in the baking tray until firm enough to lift. Use the foil overhang to lift the blondies onto a wire rack and cool completely. Remove the foil and cut into squares.