!Make the cakes:
Preheat oven to 350-degrees. Prepare two 9-inch round baking pans by applying nonstick spray, lining with parchment, and then spraying again.
Set 5-8 Oreo halves down in each pan. These will be the cream sides, with the cream facing up. Set the black halves aside to be used in the filling.
In a large bowl, stir together the sugar, flour, cocoa, baking powder, baking soda and salt.
Add the eggs, milk, oil and vanilla; beat on medium speed for about 2 minutes.
Stir in the boiling water. The batter will be very thin. Pour it very carefully into the prepared pans. Don't be surprised if the Oreos float around.
Bake the pans for 30 to 35 minutes or until wooden pick inserted in center comes out clean.
Cool them for 10 minutes; run a knife around the sides to make sure they are loose, then carefully remove the cakes from pans. Set them on wire racks and remove the parchment from the tops. Let the cakes completely cool.
!To make the filling:
Beat together the cream, sugar and vanilla until they form stiff peaks. Gently fold in the cookie crumbs.
Set up the bottom layer of the cake on the serving dish. Depending on consistency, pipe the filling onto the cake or spread it on with a spatula.
Set the top layer in place. If need be, trim the sides of the cake to make them more even.
!Make the frosting:
Melt the butter. Mix in the cocoa. Alternately beat in the powdered sugar, milk, and vanilla. Add small amounts of milk until it reaches spreading consistency.
Frost the cake around the top and sides. Apply the remaining halved Oreos around the bottom and the top; add any sliced-off cake crumbs as well.
!Store the cake in the fridge, covered by a dome, foil, or wrap. Like most chocolate cakes, it actually tastes better after the first day. It can also be frozen in slices.
!OM NOM NOM!