Preheat oven to 400ºF. Grease a 9×13″ pan.
Sift collectively flour and sugar; put aside.
In a saucepan over excessive warmth, convey butter, cocoa, and water to a boil, then pour over the sugar and flour combination. Combine effectively.
Add buttermilk and eggs, baking soda, and vanilla to flour combination and blend effectively.
Pour into ready pan. Bake for 25 minutes or till a toothpick comes out clear when inserted within the heart.
