Preheat oven to 350 degrees.
Grease a 9 by 13-inch pan.
In a large mixing bowl, combine flour, sugar, cocoa powder, salt, vegetable oil, eggs, and vanilla
Stir vigorously for about 3 minutes until the batter is well blended and creamy.
Pour into prepared pan.
Bake for 30 to 35 minutes or until a knife inserted into the center comes out clean.