Ingredients:

  • All-Purpose Flour: 1 ¾ cups (210g)
  • Granulated Sugar: 2 cups (400g)
  • Unsweetened Cocoa Powder (Dutch-processed recommended): ¾ cup (75g)
  • Baking Soda: 1 ½ teaspoons
  • Baking Powder: 1 teaspoon
  • Salt: 1 teaspoon
  • Large Eggs: 2, room temperature
  • Buttermilk: 1 cup (240ml)
  • Vegetable Oil: ½ cup (120ml)
  • Vanilla Extract: 2 teaspoons
  • Hot Strong Coffee (or hot water): 1 cup (240ml)
  • Creamy Peanut Butter (unsalted preferred): 1 ½ cups (380g)
  • Unsalted Butter, softened: ½ cup (113g)
  • Confectioners’ (Icing) Sugar, sifted: 3 cups (360g)
  • Heavy Cream (cold): 3–4 tablespoons
  • Semi-Sweet Chocolate Chips (or chopped baking chocolate): 6 ounces (170g)
  • Heavy Cream: ½ cup (120ml) (for glaze)
  • Unsalted Butter: 2 tablespoons (28g) (for glaze)
  • Pinch of Salt (for glaze)

Instructions:

  1. Prep Oven & Pan: Preheat oven to 350°F (175°C). Grease and line the bottom of the 9-inch pan with parchment paper.
  2. Combine Dry Ingredients: Whisk together flour, sugar, cocoa, baking soda, baking powder, and salt in a large bowl.
  3. Combine Wet Ingredients (Excluding Coffee): In a separate bowl, whisk eggs, buttermilk, oil, and vanilla extract until just combined.
  4. Mix Batter: Gradually add the wet mixture to the dry ingredients, mixing on low speed until just incorporated. Carefully pour the hot coffee (or water) into the batter and mix until smooth. The batter will be very thin.
  5. Bake: Pour batter into the prepared pan. Bake for 30–35 minutes, or until a wooden skewer inserted into the centre comes out with moist crumbs attached. Let the cake cool in the pan for 15 minutes before inverting it onto a wire rack to cool completely.
  6. Prepare Peanut Butter Filling: Beat the softened butter and peanut butter together until light and fluffy. Slowly add the sifted confectioners’ sugar, alternating with splashes of cold heavy cream, beating on low speed. Increase speed to medium-high and beat for 2–3 minutes until light and smooth. Stir in vanilla.
  7. Assemble: Once the cake is completely cool, spread the entire peanut butter filling evenly over the top of the cake base.
  8. Chill: Place the cake in the refrigerator for at least 30 minutes to set the filling firm.
  9. Make Glaze: Heat ½ cup heavy cream in a small saucepan until just simmering. Remove from heat, add the chocolate chips and 2 tablespoons butter, stirring gently until smooth and glossy. Add a pinch of salt and let cool slightly (about 5 minutes).
  10. Glaze and Final Chill: Pour the slightly cooled glaze over the chilled peanut butter layer, allowing it to drip down the sides. Return the cake to the fridge for at least 1 hour to allow the glaze to set firmly before slicing.