Preheat your oven to 350℉. Grease two 9-inch cake pans.
Sift together the flour, cocoa powder, sugar, baking soda, baking powder and salt in a medium-sized bowl.
In a separate medium-sized bowl, whisk together the eggs, oil and vanilla until thoroughly combined. Whisk in the buttermilk until combined.
Add the wet ingredients to the dry and add strong, hot coffee. Whisk until everything is combined. The batter is very thin. Don't worry.
Divide the batter evenly between the two pans. Bake in the centre of the oven for approx. 20-25 minutes. Gently rotate the pans halfway through. Start checking at 20 minutes. The cakes are done when a toothpick inserted into the centre comes out clean.
Cool the cakes completely in the cake pans on a wire rack.