Step 1

Place rack in the upper third of the oven and preheat oven to 350 degrees F. Grease and flour an 18×13 sheet cake pan.

Step 2

In a medium mixing bowl, combine flour, sugar, salt, and baking soda. Set aside.

Step 3

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

Step 4

In a large liquid measuring cup,  whisk together the buttermilk, beaten eggs, and vanilla. Stir buttermilk mixture into butter/chocolate/ flour mixture. Pour into sheet cake pan, spread evenly and bake for 20 minutes or until a toothpick inserted in the center comes out with a few moist crumbs not wet batter.

Step 5

While cake is baking, make the icing. Chop pecans well. Melt butter in a saucepan. Add cocoa, stir to combine, then turn off heat. Add the milk, vanilla, and powdered sugar and stir until smooth. Add the pecans.

Step 6

Pour the warm frosting over the warm cake. Allow to cool and set for at least 30 minutes. Cut into squares and enjoy! To store, wrap the cake in plastic wrap or foil and keep in the refrigerator or at room temperature.