Preheat oven to 350 degrees F. Butter three 9-inch round cake pans. Set them aside.
Whisk flour, cocoa, baking soda, baking powder, sugar and salt in a large bowl and set it aside too.
In a stand mixer/hand held mixer using whisk attachment, mix eggs, buttermilk, warm water, oil, and vanilla in a large bowl. Add all the sifted dry ingredients into wet. Meanwhile add coffee into water and heat it for a minute.
Beat on medium speed until the batter is well combined and smooth. Add hot coffee in the batter and give it a quick mix. Take care not to overmix it. Divide the batter amongst three pans.
Bake for 30-35 minutes or until a toothpick inserted into the center comes out clean. Every oven is different. So I suggest to keep an close eye on your cakes after 30 minutes have passed. You don't want to serve a dry cake! Cakes are done baking as soon as they pass toothpick test.
Cool on a wire rack for 10-15 minutes then turn out the cakes onto the racks and allow to cool completely.
Layer and frost with your favorite frosting and enjoy!