The Best Chocolate Sheet Cake

Notes: this cake is amazingly moist and not overwhelmingly chocolatey. It is rich though and does serve a lot.

Serve 24. 

Cake:
2 cups flour
2 cups sugar
1/4 teaspoon salt
4 tablespoons cocoa powder
2 sticks butter
1 cup boiling water
1/2 cup buttermilk
2 whole beaten eggs
1 teaspoon baking soda
1 teaspoon vanilla

Frosting:
1/2 cup finely chopped pecans
1-3/4 sticks butter
4 tablespoons cocoa
6 tablespoons milk
1 teaspoon vanilla
1 lb (minus 1/2 cup) powdered sugar--this equals about 3 1/2 cups

Preheat oven to 350 degrees F. Grease a large (18in x 13in) sheet pan.

In a large mixing bowl, combine flour, sugar, and salt.

In a saucepan, melt butter. Add in cocoa and stir. Add boiling water, and allow mixture to boil for 30 seconds, then turn off heat. Pour over flour mixture and stir lightly to cool.

In a measuring cup, pour the buttermilk and add beaten eggs, baking soda, and vanilla. Stir buttermilk mixture into the butter/chocolate mixture. Pour into prepared pan. Bake for 20 minutes.

While cake is baking, make the frosting. Melt butter in a saucepan. Add cocoa and stir until combined. Remove from heat. Add milk, vanilla, and powdered sugar and stir together. Add the pecans. Pour over warm cake.