Ingredients:

  • 2 cups All-Purpose Flour (sifted)
  • 1 ¾ cups Granulated Sugar
  • ¾ cup Unsweetened Cocoa Powder (Dutch-processed)
  • 1 ½ teaspoons Baking Soda
  • 1 teaspoon Baking Powder
  • 1 teaspoon Fine Sea Salt
  • 3 Large Eggs (room temperature)
  • 1 cup Buttermilk (room temperature)
  • ½ cup Vegetable Oil
  • 1 tablespoon Vanilla Extract
  • 1 cup Hot Coffee (freshly brewed)
  • 1 ½ lbs Dark Chocolate (60-70%, finely chopped)
  • 2 cups Heavy Cream (35% milkfat)
  • 4 tablespoons Unsalted Butter (cubed)
  • ½ cup Powdered Sugar (optional, for frosting)

Instructions:

  1. Preheat oven to 350°F (175°C). Grease and line two 8-inch round cake pans with parchment circles.
  2. Whisk all dry sponge ingredients (flour through salt) in a large bowl.
  3. In a separate bowl, whisk eggs, buttermilk, oil, and vanilla. Gradually add wet mixture to dry ingredients and mix until just combined.
  4. Slowly pour in the hot coffee, mixing until the batter is smooth and thin.
  5. Bake the first batch (half the batter) by dividing it evenly between the two pans for 12–15 minutes. Layers must be very thin (approx. 1/4 inch thick).
  6. Cool layers for 5 minutes, then invert onto racks. Immediately use a template or pan to trim edges for uniformity while warm. Repeat the baking process with the remaining batter to yield 24 layers total. Allow all layers to cool completely.
  7. Prepare the Ganache: Bring heavy cream to a simmer, then pour over the chopped chocolate. Let sit for 5 minutes, then whisk gently until smooth.
  8. Whisk in the softened butter until fully emulsified. If using, whisk in powdered sugar. Chill until firm enough to whip lightly (1-2 hours).
  9. Assemble the cake: Place the first layer on a serving plate. Spread a thin, even layer of whipped ganache on top.
  10. Carefully stack the next layer and repeat the frosting and stacking process until all 24 layers are used.
  11. Apply a thin crumb coat to the exterior and chill for 30 minutes to set the structure.
  12. Apply the final, smooth coating of ganache to the top and sides of the cake tower.
  13. Chill the assembled cake for a minimum of 4 hours, preferably overnight, before slicing and serving.