Best Brownies

1/2 cup butter, melted
1 cup sugar
1 teaspoon vanilla
2 eggs
1/2 cup unsifted flour
1/3 cup cocoa
1/4 teaspoon baking powder
1/4 teaspoon salt
1/2 cup chopped nuts, optional


Blend butter, sugar, and vanilla in large bowl. Add eggs, using a wooden spoon, beat well. Combine flour, cocoa, baking powder and salt; gradually blend into egg mixture. Stir in nuts. Spread in greased 9" square pan. Bake 20-25 minutes at 350.