Ingredients:

  • 2 cups (250g) all-purpose flour
  • 2 cups (400g) granulated sugar
  • 3/4 cup (75g) unsweetened cocoa powder
  • 2 tsp (10g) baking soda
  • 1 tsp (5g) baking powder
  • 1 tsp (5g) salt
  • 1 cup (240ml) buttermilk
  • 1/2 cup (120ml) vegetable oil
  • 2 large eggs
  • 2 tsp (10ml) vanilla extract
  • 1 cup (240ml) boiling water
  • 1/2 cup (115g) unsalted butter
  • 1/3 cup (30g) unsweetened cocoa powder
  • 3 cups (560g) powdered sugar
  • 1/3 cup (80ml) milk
  • 1 tsp (5ml) vanilla extract

Instructions:

  1. Preheat oven to 350°F (175°C) and grease a 9x13-inch baking pan.
  2. In a large mixing bowl, whisk together the flour, granulated sugar, 75g cocoa powder, baking soda, baking powder, and salt until no clumps remain.
  3. Add buttermilk, vegetable oil, eggs, and 10ml vanilla extract to the dry ingredients. Whisk by hand until the batter is smooth and glossy.
  4. Carefully stir in the boiling water until combined. The batter will be thin.
  5. Pour batter into the prepared pan and bake for 30–35 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs.
  6. Allow the cake to cool completely on a wire rack for 1 hour.
  7. Prepare the glaze by melting the butter, whisking in 30g cocoa powder, then gradually stirring in powdered sugar, milk, and 5ml vanilla extract until smooth.
  8. Pour the chocolate glaze over the cooled cake and spread evenly.