Combine 3/4 cup sugar, flour, 3 Tablespoons cocoa, baking powder and salt.
Blend in milk, butter and vanilla. Beat until smooth.
Pour batter into oiled 10 inch iron skillet.
Combine remaining sugar, brown sugar, 4 Tablespoons cocoa and sprinkle over batter.
Pour hot water on top.
Bake at 350 degrees for 30-35 minutes.
Let stand 15 minutes before serving. If desired, top with whipped cream and/or ice cream.