Absolutely Best Brownies

Ingredients1/2 cup butter, melted 1 cup white sugar2 eggs1/2 cup self-rising flour1/3 cup unsweetened cocoa powder1/4 teaspoon salt1 teaspoon vanilla extract 1/2 cup chopped walnuts (optional) DirectionsPreheat oven to 350 degrees F (175 degrees C). Grease and flour an 8×8 or 9×9 inch baking pan.In a medium bowl, beat together the butter and sugar. Add …