Blend melted butter, sugar, and vanilla in a mixing bowl. Add eggs, beat well with spoon. Combine flour, cocoa, baking powder, and salt; gradually add to egg mixture until well blended.

Spread mixture in a greased 8-inch square pan. Bake for 40-45 minutes or until brownie begins to pull away from edges of pan. Cool.

Cut into squares.

Makes 12 brownies.

Optional additions: 3/4 cup chopped walnuts or pecans, or 1/2 cup chocolate or peanut butter chips.