| Preheat oven to 350 degrees F. In a large bowl, stir together flour, white sugar, cocoa, baking powder and salt. Mix in milk, oil, and vanilla with a fork until smooth. Spread batter evenly into ungreased 9x13 inch pan, batter will be thick. Sprinkle with brown sugar and cocoa. Pour boiling water over batter. Bake for 35 minutes. Let stand 10 minutes. Spoon into dessert dishes or cut into squares. Invert each square onto dessert plate and spoon sauce over each serving. Top with ice cream or whipped topping, if desired. | 
