Katherine's Amazing Chocolate Cake

The name says it all.

1. Grease and flour a 9" X 12" (24 X 30cm) cake pan.
2. Preheat the oven to 350F degrees (180C)
3. Sift:
   2-1/2 cups plain flour
   2 cups sugar
   6 tablespoons unsweetened cocoa powder
   2 teaspoons baking soda
   1 teaspoon salt
4. Pour over dry ingredients and mix well until smooth:
   1/2 cup cooking oil
   2 teaspoons vanilla
   2 tablespoons vinegar
   2 cups cold water
5. Pour in pan and bake at 350F (180C) for 35 minutes.
   The cake is ready when it bounces back to the touch or a toothpick comes out clean.