Since you bake it in a jellyroll pan, this cake feeds a crowd - so moist, rich and delicious. Comes together quickly with minimal mess. Great for a last-minute picnic invitation.
Yield: 1 big-ole cake, 10 1/2 x 15 1/2. Enough for a big ole party.
In a large saucepan, bring butter, cocoa, salt, and water to a boil.
Preheat oven to 375°F.
Prepare a baking sheet - a 10 1/2 x 15 1/2 edged cookie sheet - a jelly roll pan or one of those large cookie sheets with sides.
Remove from heat and allow to cool down. (You may want to move it into a mixing bowl; the heat of the pan will keep the mixture hot longer.) Stir in vanilla. When mixture is sufficiently cooled, stir in flour, sugar, sour cream, eggs, and baking soda. Be sure the eggs are thoroughly combined.
You don't want to add the eggs while the mixture is too hot or they'll cook in the batter without becoming part of the batter...like if there was a hunk of fried egg in the middle of your piece of cake. Not optimal. The same thing can happen if the eggs aren't totally incorporated into the batter.
Bake in the prepared pan at 375°F for 20-25 min.
While cake is baking, prepare the icing. (You'll be spreading it over the hot cake.) In a small saucepan, bring 4 Tbsp. butter, 4 Tbsp. of milk, 3 Tbsp. of cocoa and 1 tsp. vanilla to a boil. Remove from heat, and beat in powdered sugar until it looks like frosting - a spreadable consistency. (Don't worry if you add a little too much and it gets too stiff, just add a little more milk.)
Submitted by Gretchen Grant Contributed on: and modified on Friday March 11th, 2011