Chewy and delicious brownies with sweet and creamy white chocolate chunks.
Preheat oven to 350º. Grease an 8-inch square baking pan. Set aside. Melt unsweetened chocolate and butter in small, heavy saucepan over low heat, stirring constantly. Set aside. Beat eggs in large bowl with electric mixer at medium speed for 30 seconds. Gradually add granulated sugar, beating at medium speed about 4 minutes until very thick and lemon-colored. Beat in chocolate mixture and vanilla. Mix in flour and salt at a low speed until just blended. Stir in baking bar pieces and walnuts with mixing spoon. Spread batter evenly in prepared baking pan. Bake 30 minutes or until edges just begin to pull away from the sides of the pan and the center is set. Remove pan to wire rack. Cool completely. Cut into 2-inch squares. Place powdered sugar in fine-mesh sieve and dust brownies, if desired. Store tightly covered at room temperature or freeze for up to 3 months. Make 16 brownies.