1 c. butter
1/2 c. cocoa

Melt together. Beat until fluffy in separate bowl:

4 eggs
2 c. sugar
1 tsp. vanilla
1 c. flour

Pour egg mixture into cocoa mixture. Stir together swiftly until combined. Add 1 cup flour. Pour into 9 x 13 inch pan. Bake at 350 degrees for 25 minutes.