Preheat the oven to 350°F and grease and flour two 9-inch round cake pans.
In a big bowl, mix the flour, sugar, baking soda and salt.
In a medium saucepan over medium heat, melt the butter. Whisk in the coffee, cocoa powder and 1/2 cup water and heat it for a minute, stirring constantly. Pour the melted butter mixture into the flour mixture and whisk until well-combined.
In a medium bowl, whisk the eggs, buttermilk and vanilla. Add it to the batter and mix until smooth.
Divide the batter between the two cake pans, scraping all the batter from the bowl with a rubber spatula. Bake for about 40 minutes, or until a toothpick inserted into the center of the cake comes out clean. Let cool for 15 minutes in the pans and then turn out onto a wire rack to cool completely.
Frost with the frosting of your choice.
Variation: The water/coffee combo in this recipe can be switched up, but remember, coffee is to chocolate like salt is to beef: Coffee brings out the flavor of chocolate without making it taste like coffee, just as salt brings out the flavor of meat without making it taste salty. The liquid you use can be all water or it can be a full cup of coffee for more of a mocha-flavored cake. And if you’re feeling really bold, go ahead and use a cup of a dark stout beer instead. Top it with an Irish cream buttercream. Get creative and experiment a little – after all, it is a science project!MORE
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