Preheat oven to 350°F. Line two 8-inch round cake pans with parchment paper and spray with baking spray.

In a large bowl, whisk together flour, cocoa powder, sugar, baking powder, baking soda, and salt.

Stir in vegetable oil until dry ingredients are well coated, followed by eggs and vanilla.

Stir in buttermilk until combined, then carefully pour in hot coffee and stir until smooth.

Add batter evenly to prepared cake pans and bake in preheated oven for 30-35 minutes, or until a toothpick entered into the center of the cakes comes out smooth or with moist crumbs.

Cool cake layers slightly in cake pans, then transfer to a wire rack to cool completely before adding Chocolate Fudge Frosting.

Prepare frosting as detailed in Chocolate Fudge Frosting post.

Spread frosting over cooled cake layers.

Chocolate Fudge Frosting:

Heat heavy cream in a saucepan over medium heat until it is hot, but not boiling. You'll begin to see little bubbles forming around the edges of the pan.

Reduce heat to low. Sift in cocoa powder, powdered sugar, and espresso powder. Whisk well until fully combined and smooth.

Add in chopped chocolate and cubed butter. Stir until melted and mixture is smooth. Stir in vanilla extract.

Pour mixture into a heatproof bowl and cover with plastic wrap so that it is touching the top of the mixture -- this way it won't develop a film on top.

Let frosting cool at room temperature for around 45 minutes -- less for a thinner frosting, and more for a thicker frosting.