In an ungreased 8-inch square pan,sift flour, brown sugar, salt, soda, and cocoa. Mix them until they are blended together.
Stir in the remaining wet ingredients - water ,oil, vinegar and vanilla extract. Use a spatula to blend the ingredients in and spread the batter evenly.
Sprinkle the batter with chocolate chips and granulated sugar.
Bake at 350 degrees F (175 degrees C) for 35 to 40 minutes, or until tooth pick inserted comes out clean.
Cool the pan in a cooling rack for 15 minutes and serve warm