Update October 8, 2024: The complete guide to making this wonderful cake can be found at Ina Garten Chocolate Cake. 
I know it’s annoying when people start a recipe name with “the best…”, but I don’t care, this really is the best chocolate layer cake recipe. Even Ina says so. This recipe comes from Ina Garten’s Barefoot Contessa at Home cookbook. It’s super rich and has a cup of coffee in the batter, which complements the chocolate perfectly. I made this today for one of my best girlfriend’s birthdays and it was a big hit all around.
 
The cake stays very moist, the buttercream is super rich, and the best part of all – the batter is the easiest to make and is almost all done in one bowl.