Ingredients:

  • 2 cups (240g) All-purpose flour
  • 2 cups (400g) Granulated sugar
  • ¾ cup (75g) Unsweetened cocoa powder
  • 2 tsp (10g) Baking soda
  • 1 tsp (5g) Salt
  • 1 cup (240ml) Buttermilk, room temperature
  • ½ cup (115g) Vegetable oil
  • 2 Large eggs, room temperature
  • 1 tsp (5ml) Vanilla extract
  • 1 cup (240ml) Boiling water
  • 1 cup (225g) Unsalted butter, softened
  • 1 cup (250g) Creamy peanut butter
  • 3 cups (360g) Powdered sugar
  • 2 tbsp (30ml) Heavy cream
  • 4 oz (115g) Semi-sweet chocolate, finely chopped
  • ½ cup (120ml) Heavy cream

Instructions:

  1. Preheat your oven to 350°F (175°C) and grease your baking pan. In a large bowl, whisk together the flour, sugar, cocoa powder, baking soda, and salt.
  2. Add the buttermilk, vegetable oil, eggs, and vanilla extract to the dry ingredients, beating on medium speed until well combined. Stir in the boiling water by hand until the batter is smooth.
  3. Pour the batter into the prepared pan and bake for 25-30 minutes, or until the center springs back when lightly pressed. Let the cake cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.
  4. In a clean bowl, beat the softened butter and peanut butter together until pale and fluffy. Gradually add the powdered sugar one cup at a time, then stir in 2 tablespoons of heavy cream. Beat on high for 2 minutes until light and airy, then spread evenly over the cooled cake.
  5. Place chopped chocolate in a bowl. Heat the remaining heavy cream until simmering, pour it over the chocolate, let sit for 5 minutes, and stir until smooth and glossy. Pour the ganache over the frosted cake and let set for 30 minutes.