Ingredients:

  • 95 g all-purpose flour
  • 100 g granulated sugar
  • 25 g unsweetened cocoa powder
  • 3 g baking soda
  • 1 g baking powder
  • 1.5 g fine salt
  • 80 ml buttermilk, room temperature
  • 80 ml hot water
  • 2 g instant espresso powder
  • 60 ml vegetable oil
  • 1 large egg (50 g), room temperature
  • 2.5 ml vanilla extract
  • 113 g unsalted butter, softened
  • 180 g powdered sugar
  • 30 g unsweetened cocoa powder
  • 45 ml whole milk or heavy cream
  • 2.5 ml vanilla extract
  • 0.3 g fine salt (pinch)

Instructions:

  1. Heat the oven to 180°C (350°F). Grease two 6-inch round pans and line the bottoms with parchment circles.
  2. In a medium bowl, whisk the flour, sugar, cocoa powder, baking soda, baking powder and salt until no cocoa streaks remain. Sift the cocoa first if it is clumpy.
  3. In a small bowl, stir the espresso powder into the hot water until dissolved. Add to the dry ingredients and whisk until smooth. The batter will be thick and dark.
  4. Add the buttermilk, vegetable oil, egg and vanilla. Whisk for about 1 minute, until glossy with no dry pockets. Stop as soon as the batter is uniform.
  5. Divide the batter evenly between the two pans, about 250 g each. Smooth the tops with a spatula.
  6. Bake for 22 to 25 minutes, rotating the pans halfway through if your oven bakes unevenly. The layers are done when the tops spring back lightly and a toothpick inserted in the center comes out with a few moist crumbs, not wet batter.
  7. Rest the layers in their pans for 10 minutes. Loosen the edges with a knife, turn them onto a wire rack, peel off the parchment and cool completely, about 1 hour.
  8. Beat the softened butter with a hand mixer on medium speed for 1 to 2 minutes, until smooth and creamy.
  9. Sift the powdered sugar and cocoa powder into the bowl, add the salt and beat on low speed until combined.
  10. Add the vanilla and milk, then beat on medium-high for 2 minutes. The frosting should be thick, smooth and spreadable. If it is too stiff, add milk 1 teaspoon at a time.
  11. Place one cooled layer top-side down on a serving plate. Spread about 1/3 cup of frosting over the top. Set the second layer on top, top-side up.
  12. Spread a thin crumb coat over the sides and top. Refrigerate for 15 minutes.
  13. Apply the remaining frosting, smooth the sides with an offset spatula and swirl the top. Slice and serve.