3.38 ounces all-purpose flour (about 3/4 cup)
1 cup granulated sugar
3/4 cup unsweetened cocoa
1/2 cup packed brown sugar
1/2 teaspoon baking powder
1/4 teaspoon salt
1 cup bittersweet chocolate chunks, divided
1/3 cup fat-free milk
6 tablespoons butter, melted
1 teaspoon vanilla extract
2 large eggs, lightly beaten
1/2 cup chopped walnuts, divided
Cooking spray

3 38 ounces all-purpose flour (about 3/4 cup) 1 cup granulated sugar 3/4 cup unsweetened cocoa 1/2 cup packed brown sugar 1/2 teaspoon baking powder 1/4 teaspoon salt 1 cup bittersweet chocolate chunks, divided 1/3 cup fat-free milk 6 tablespoons butter, melted 1 teaspoon vanilla extract 2 large eggs, lightly beaten 1/2 cup chopped walnuts, divided

1. Preheat oven to 350°.

2. Weigh or lightly spoon flour into dry measuring cups; level with a knife. Combine flour and next 5 ingredients (through salt) in a large bowl. Combine 1/2 cup chocolate and milk in a microwave-safe bowl; microwave at HIGH 1 minute, stirring after 30 seconds. Stir in butter, vanilla, and eggs. Add milk mixture, 1/2 cup chocolate, and 1/4 cup nuts to flour mixture; stir to combine.

3. Pour the batter into a 9-inch square metal baking pan coated with cooking spray; sprinkle with remaining 1/4 cup nuts. Bake at 350° for 22 minutes or until a wooden pick inserted in center comes out with moist crumbs clinging. Cool in pan on a wire rack. Cut into 20 pieces.