I've had my share of chocolate cakes and this one is truly a keeper! My boy can eat half the sheet if I allow him to! This Ultimate Texas Chocolate Sheet Cake is so delicious, super moist, and with a tender light crumb. So good.
Preheat the oven to 350 F. Mix together the flour, sugar, salt and baking soda. Set aside.
Mix together the buttermilk, eggs, and vanilla extract. Set aside.
In a small saucepan, melt the butter on low. Add the cocoa powder and pour in the hot coffee and stir until blended. Turn off the heat. Stir cocoa mixture into the flour mixture and mix until well-blended.
Pour in the buttermilk mixture to the flour mixture. Stir gently but thoroughly avoiding over mixing the batter. Pour the batter into a greased 13x18 sheet pan.
Bake the cake for about 20 minutes or until a tester inserted in the middle of the cake comes out with only a few crumbs. Transfer to a rack and cool for about 15 minutes.
In a small saucepan, bring the milk, cocoa powder and butter to a boil. Immediately remove from heat. Alternatively and as a shortcut, simply microwave the butter with the cocoa in a glass bowl until the butter is melted. Add the milk, vanilla extract and icing sugar and beat until smooth. Adjust the thickness or consistency of the frosting by adding or lessening the amount of milk and sugar. Add the pecans or walnuts, if using. Spread the frosting over the warm cake in the baking sheet. Cool or serve warm with vanilla ice cream or whipped cream!!! This can be made ahead and tastes even better the next day.