Aunt Kathy Jo introduced this recipe to me last year and I almost made myself sick eating it.  I'm not a big chocolate cake fan but there's something about this one that will bring me to making one for Thanksgiving.
Best Ever
Chocolate
Sheet Cake
(from Kathy Jo)
      
CAKE RECIPE 
 ½ C. Crisco 
1 stick real butter 
 3 ½ Tbs cocoa 
 1 C. water 
 ½ tsp salt 
 2 C. sugar 
 2 C. flour 
 1 tsp. vanilla 
 2 eggs 
 ½ C. buttermilk 
 1 tsp. soda 
  
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ICING RECIPE 
 1 stick real butter 
 3 ½ Tbs. cocoa 
 1/3 C. milk 
 1 box powdered sugar 
 1 tsp. vanilla 
 1 C. pecans 
  
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Sauce  Pan – Crisco, butter, cocoa, water, salt; bring to a boil.  Mix sugar and flour in bowl; pour the mixture in saucepan.  Add 1 tsp. vanilla, 2 eggs, ½ C buttermilk, and 1 tsp. cocoa.
  
Pour into a 9x13 greased & floured pan.  Bake for 20 minutes at 400 degrees.  Do not overcook!
Five minutes before cake is done, mix in saucepan 1 stick butter, 3 ½ Tbs. cocoa & 1/3 C. milk.  Boil.  Add 1 box of powdered sugar, 1 tsp. vanilla & pecans. Pour over warm cake.