Chocolate Cookie Sheet Cake - Vintage Recipe

My uncle gave me a vintage cookbook a while back called Virginia Hospitality.  It's a Junior League cookbook from the year I was born, 1975.  Recently I made this recipe called Chocolate Cookie Sheet Cake from the book - and it is amazing.  I modified it just slightly.  It is so good that I knew I had to share it with my readers (plus, my Mom was begging for the recipe - this way I am multitasking!).  You bake this cake right on a cookie sheet that has 1 inch raised sides (or, in my case, I used a sheet cake pan).

Ingredients for cake:
2 cups flour
2 cups sugar
1/2 tsp. salt
1/2 cup butter
1 cup water
1/2 cup shortening
4 tbsp. cocoa
3 eggs, beaten
1 tsp. baking soda
1/2 cup buttermilk (I used milk w/ vinegar)
1 tsp. vanilla

Preheat oven to 350*.  Grease and flour an 11x17 inch cookie sheet.  Sift together flour, sugar, salt; set aside.  In a saucepan, combine butter, water, shortening and cocoa and bring to a boil; pour over flour mixture.  Mix well.  In another bowl, beat eggs, add soda, buttermilk, and vanilla.  Stir well and add to first mixture.  Mix well.  Bake for 20-25 minutes.  Start icing during the last 5 minutes of baking.

Ingredients for icing:
1/2 cup butter
4 tbsp. cocoa
2 cups confectioner's sugar
1 tsp. vanilla
pinch of salt
6 tbsp. buttermilk

In a saucepan, melt butter and cocoa, but DON'T BOIL.  Take from heat and add remaining ingredients.  Ice cake while hot.  Yield:  35 servings

It makes a lot, so this recipe is perfect for a bake sale or a potluck.  Or for a family filled with hungry little boys, like mine.  Enjoy it!