Ingredients:

  • 2 ¼ cups (281g) all-purpose flour
  • 2 ½ teaspoons baking powder
  • ½ teaspoon baking soda
  • ½ teaspoon salt
  • ¾ cup (1 ½ sticks / 170g) unsalted butter, softened
  • 1 ¾ cups (350g) granulated sugar
  • 2 large eggs
  • 1 teaspoon vanilla extract
  • 1 ¼ cups (296ml) buttermilk
  • 6 Oreo cookies, finely crushed (about 1/2 cup)
  • 1/4 cup (59ml) brewed coffee, cooled (optional)
  • 1 ½ cups (3 sticks / 340g) unsalted butter, softened
  • 6 cups (720g) powdered sugar, sifted
  • ½ cup (118ml) heavy cream
  • 2 teaspoons vanilla extract
  • 1/4 teaspoon salt
  • 15 Oreo cookies, finely crushed (about 1 1/4 cups)
  • 6 Oreo cookies, halved or quartered (optional)
  • Chocolate shavings (optional)

Instructions:

  1. Grease and flour the cake pans. Line the bottoms with parchment paper rounds.
  2. In a bowl, whisk together flour, baking powder, baking soda, and salt.
  3. In a separate bowl, cream together butter and sugar until light and fluffy.
  4. Beat in eggs one at a time, then stir in vanilla extract.
  5. Gradually add the dry ingredients to the wet ingredients, alternating with buttermilk, beginning and ending with the dry ingredients. Mix until just combined.
  6. Fold in the crushed Oreo cookies. Add cooled coffee (optional).
  7. Divide the batter evenly among the prepared cake pans. Bake at 350°F (175°C) for 30-35 minutes, or until a toothpick inserted into the center comes out clean.
  8. Let the cakes cool in the pans for 10 minutes, then invert onto a wire rack to cool completely.
  9. In a large bowl, cream butter until smooth and fluffy. Gradually add powdered sugar, alternating with heavy cream, beating until light and fluffy. Mix in vanilla extract and salt.
  10. Gently fold in the crushed Oreo cookies.
  11. Level the cake layers using a serrated knife if necessary. Place one cake layer on a cake stand or serving platter. Spread with a generous layer of Oreo buttercream frosting. Repeat with the remaining cake layers.
  12. Frost the entire cake with the remaining Oreo buttercream frosting. Use an offset spatula to create a smooth finish or decorative swirls.
  13. Decorate with halved or quartered Oreo cookies and chocolate shavings (optional).
  14. Chill the cake for at least 30 minutes before serving to allow the frosting to set.