Ingredients:

  • 2.5 cups (315g) all-purpose flour
  • 1.5 cups (300g) granulated sugar
  • 0.5 cup (100g) light brown sugar, packed
  • 1 tsp baking powder
  • 0.5 tsp baking soda
  • 0.75 tsp fine sea salt
  • 0.5 cup (113g) unsalted butter, softened
  • 0.75 cup (185g) creamy peanut butter (standard brand)
  • 3 large eggs, room temperature
  • 1 tbsp pure vanilla extract
  • 1 cup (240ml) buttermilk, room temperature
  • 0.25 cup (60ml) neutral vegetable oil
  • 1 cup (250g) creamy peanut butter (for frosting)
  • 0.5 cup (113g) unsalted butter, softened (for frosting)
  • 3 cups (375g) powdered sugar, sifted
  • 4 tbsp heavy cream
  • 1 tsp vanilla extract (for frosting)

Instructions:

  1. Preheat your oven to 180°C (350°F) and grease two 8-inch round cake pans, lining the bottoms with parchment paper.
  2. In a stand mixer fitted with the paddle attachment, cream the 113g of butter, 300g granulated sugar, and 100g brown sugar together for 5 minutes until pale and fluffy.
  3. Add the 185g of creamy peanut butter and 60ml oil to the butter mixture, beating until completely smooth and integrated.
  4. Add the 3 large eggs one at a time, beating well after each addition until the batter looks like liquid gold. Stir in the 1 tbsp vanilla extract.
  5. Whisk the 315g flour, baking powder, baking soda, and salt together. Add 1/3 of the dry ingredients to the bowl, then 1/2 of the 240ml buttermilk, repeating until just combined and no white streaks remain.
  6. Divide the batter between the two prepared pans. Bake for 30-35 minutes until a toothpick comes out with just a few moist crumbs.
  7. Let the cakes cool in the pans for 10 minutes, then invert onto a wire rack until completely cold to the touch.
  8. In a clean bowl, beat the 250g peanut butter and 113g butter until creamy and light.
  9. Gradually add the 375g sifted powdered sugar, 4 tbsp heavy cream, and 1 tsp vanilla. Beat on high for 3-4 minutes until the frosting is silky and holds a soft peak.
  10. Place one cake layer on a plate, spread a generous layer of frosting, and top with the second layer. Frost the top and sides until the cake is fully encased in nutty silk.