Hot Fudge Cake

1 cup all-purpose flour
3/4 cup white sugar
6 tablespoons baking cocoa, divided
2 teaspoons baking powder
1/4 teaspoon salt
1/2 cup milk
2 tablespoons vegetable oil
1 teaspoon vanilla extract
1 cup packed brown sugar
1-3/4 cups hot water

In a medium bowl, combine flour, sugar, 2 tablespoons cocoa, baking powder, and salt.   Stir in the milk, oil, and vanilla until smooth.  Spread in an ungreased 9-inch square baking pan.  Combine brown sugar and remaining cocoa; sprinkle over batter.  Pour hot water over all; do no stir.  Bake at 350 degrees F. for 35-40 minutes.  Serve warm.

Great right out of the oven topped with ice cream or whipped cream.