Step 1

Heat oven to 350°F. Grease 13x9x2-inch baking pan or two 8- or 9-inch square pans.

Step 2

Place butter in large microwave-safe bowl. Microwave at medium (50%) 2 to 2-1/2 minutes or until melted. Stir in sugar and vanilla. Add eggs, one at a time, beating well with spoon after each addition. Add cocoa; beat until well blended. Add flour, baking powder and salt; beat well. Stir in nuts, if desired. Pour batter into prepared pan or pans.

Step 3

Bake 30 to 35 minutes for 13 x 9 x 2-inch pan (20 to 22 minutes for 8- or 9-inch pans) or until brownies begin to pull away from sides of pan. Cool completely in pan on wire rack. Prepare and frost brownie with Creamy Brownie Frosting, if desired. Garnish frosted brownies with milk chocolate chips, if desired. Cut into bars.