"Why this recipe works:For this Chocolate Layer Cake recipe, we recommend Dutch-processed cocoa, which has a better flavor. “Blooming” the cocoa powder and unsweetened chocolate with hot water and instant espresso produced the strongest chocolate flavor. Sour cream added moisture and tangy flavor, while baking powder and baking soda united to create the greatest rise. This Chocolate Layer Cake recipe can be combined with many frostings and fillings for a different result every time...."