- CONTINUATION Cake: In a bowl, combine coarsely crushed Oreos with flour, baking soda, and baking powder. Set aside. In another bowl, cream butter and sugar until light and then beat in, one at a time, the egg yolks. Beat in the sour cream, melted chocolate and vanilla. Add water all at once and stir to combine. Fold in the dry ingredients and beat at medium speed on an electric mixer for 2 minutes. Beat egg whites until stiff peaks form. Fold into batter by hand. Divide the batter between the two pans (one with a cookie bottom, one plain). Bake at 350 degrees until the cake just starts to spring back when touched lightly in the center (15-25 minutes). The layer with the cookie bottom will take about 5 minutes longer than the other one. Cool layers completely and chill in refrigerator. Filling: In a bowl, combine the butter, confectioner's sugar and vanilla. Add enough milk to make a spreading consistency. Place cooled layer with cookie crust on the bottom in the center of a glass plate. Reserving some filling for garnish, spread filling over this layer. Frosting: In a bowl, combine the butter, confectioner's sugar, cocoa, and vanilla. Add enough milk to make a spreading consistency. Place remaining cooled layer over filling and spread on frosting. Garnish: Press additional crushed Oreos around the sides of the cake. Use a pastry bag to pipe reserved white filling on top to make little clumps. Press a half a miniature oreo in center of each one. MM by Mary Wilson, BWVB02B. -----