Ingredients:

  • 2 cups all-purpose flour
  • 2 cups granulated sugar
  • 3/4 cup black cocoa powder
  • 2 tsp baking soda
  • 1 tsp baking powder
  • 1 tsp salt
  • 1 cup buttermilk
  • 1/2 cup vegetable oil
  • 2 large eggs
  • 2 tsp vanilla extract
  • 1 cup boiling water
  • 1 cup unsalted butter
  • 1 1/2 cups cocoa powder
  • 5 cups powdered sugar
  • 1/2 cup heavy cream
  • 1 tsp vanilla extract
  • 1/4 tsp salt

Instructions:

  1. Preheat the oven to 350°F (175°C). Grease three 8-inch round cake pans and line the bottoms with parchment paper.
  2. In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, black cocoa powder, baking soda, baking powder, and salt.
  3. Add the buttermilk, vegetable oil, eggs, and vanilla extract to the dry ingredients, beating until the batter is smooth and ribbon-like.
  4. Stir in the boiling water by hand until combined; the batter will be thin.
  5. Divide the batter evenly between the three pans and bake for 30–35 minutes, or until a toothpick inserted comes out with just a few moist crumbs.
  6. Cool the cakes in the pans for 10 minutes before transferring them to a wire rack to cool completely.
  7. Whip the softened unsalted butter until creamy, then sift in the cocoa powder and powdered sugar.
  8. Slowly stream in the heavy cream and vanilla extract, beating on high until the frosting is glossy and spreadable.
  9. Place one cake layer on a plate, spread a thick layer of frosting, and repeat with the remaining layers.
  10. Finish by coating the top and sides of the cake in a smooth, heavy layer of fudge frosting.