HOW TO MAKE IT :
- Preheat oven to 350°F and spray two 8-inch round cake pans with nonstick cooking spray, or prepare with GOOP. Set aside.
- Sift the flour, sugar, cocoa, baking soda, baking powder, and salt into a large bowl and mix until combined.
- In another bowl, combine the buttermilk, oil, eggs, and vanilla.
- With the mixer on low speed, slowly add the wet ingredients to the dry. With the mixer still on low, add the coffee and mix just to combine. Scrape the bottom and sides of the bowl with a rubber spatula.
- Equally pour the batter into the prepared pans and bake for 30 to 40 minutes, or until a cake tester or toothpick comes out mostly clean (not wet). Cool in the pans for 30 minutes, then turn them out onto a cooling rack and cool completely.
- In the bowl of an electric mixer, beat the butter until light and smooth.
- Slowly add 2 cups of confectioners’ sugar and mix until smooth. Pause to scrape the sides of the bowl if necessary.
- 2 cups at a time, add the remaining confectioners’ sugar, mixing until combined.
- Fold in Oreo crumbs, and mix until smooth.
- Add milk 1 tablespoon at a time, until you get the consistency you desire.
- Level the cakes and place one on a serving plate.
- Spread about 1 cup of buttercream evenly on the top, followed by a few of the coarsely chopped Oreo cookies.
- Add the second layer of cake and top with the remaining buttercream and more chopped Oreo cookies.