I love this recipe! No margarine, easy to make, and freezes beautifully. I make 4 recipes at once, and YUM, the house smells great and the result is tasty!
1/2 cup oil
2 cup sugar
2 teaspoon vanilla
4 eggs
1 cup flour
2/3 cup cocoa
1 teaspoon baking powder
1 teaspoon salt (I usually skip this)

Mix all together.
Pour into a 9 x 13 pan or cookie sheet
Bake at 350 for 30-40 minutes, until sides are hardening. 
Note: It should be soft when you take it from oven, but not "liquidy"