Homemade Brownies

¾ cup melted butter
1 ½ cup sugar
1 ½ tsp. vanilla
3 eggs
1 cup flour
¾ cup cocoa
½ tsp. baking powder
½ tsp. salt

Blend all ingredients together. Spread in greased 9x13 pan. Bake at 350° for 40-45 minutes. Frost if desired or sprinkle with powdered sugar.