Preheat oven to 350°. Bake pecans in a single layer in a shallow pan 6 to 8 minutes or until lightly toasted and fragrant.
Microwave chocolate and butter in a large microwave-safe bowl at HIGH 1 to 1 1/2 minutes or until melted and smooth, stirring at 30-second intervals. Whisk in sugar and eggs until well blended. Stir in flour. Spread batter into a greased 13- x 9-inch pan.
Bake at 350° for 25 to 30 minutes or until a wooden pick inserted in center comes out with a few moist crumbs.
Prepare Chocolate Frosting. Pour over warm brownies; spread to edges. Sprinkle with pecans. Let cool 1 hour on a wire rack. Cut into squares.
Try these twists!
Mississippi Mud Brownies: Prepare recipe as directed through Step Sprinkle warm brownies with toasted pecans and 3 cups miniature marshmallows. Prepare Chocolate Frosting as directed, and pour over pecans and marshmallows. Cool 1 hour on a wire rack. Cut into squares.
Caramel-Pecan Brownies: Prepare recipe as directed through Step Cool 1 hour on a wire rack. Combine 1 cup firmly packed dark brown sugar, 1/2 cup milk, 2 Tbsp. butter, and 1/4 tsp. salt in a large saucepan; bring to a boil over medium-high heat, stirring occasionally. Reduce heat to medium-low, and simmer, stirring occasionally, 5 minutes or until slightly thickened. Remove from heat. Let stand 5 minutes. Beat in 1 1/2 cups powdered sugar and 1/2 tsp. vanilla extract at medium speed with an electric mixer until smooth. Pour over brownies, spreading to edges; sprinkle with toasted pecans. Cool 30 minutes. Hands-on time: 25 min; Total time: 2 hr., 20 min.
Marbled Brownies: Omit pecans and Chocolate Frosting. Preheat oven to 325°. Prepare batter as directed; spread half of batter into greased pan. Beat 1 (8-oz.) package softened cream cheese, 1/4 cup sugar, 1 egg yolk, and 1 tsp. vanilla extract at medium speed with an electric mixer until smooth. Dollop cream cheese mixture over brownie batter in pan. Dollop with remaining brownie batter, and swirl together using a paring knife. Bake 35 to 40 minutes. Cool 1 hour on a wire rack. Hands-on time: 30 min. Total time: 2 hr., 5 min.