2 c. flour
1 c. sugar
1/2 c. unsweetened cocoa
1 tsp. baking soda
1 1/2 tsp. baking powder
1 c. mayonnaise
1 c. water
1 tsp. vanilla

Grease 9 x 9 inch pan. Mix first 5 ingredients in large bowl. Stir in mayonnaise. Gradually stir in water and vanilla. Pour into pan. Bake at 350 degrees for 40-45 minutes.