Prepare cake batter and bake as directed on package for 24 cupcakes; cool completely.
Microwave semi-sweet chocolate and whipping cream in a small bowl for 1 to 1 ½ minutes or until chocolate is completely melted and mixture is well blended, stirring after 1 minute. Dip tops of cupcakes in chocolate glaze. Refrigerate for 10 minutes or until firm.
Beat cream cheese and butter in a large bowl with mixer until well blended. Add milk and vanilla; mix well. Beat in powdered sugar until well blended. Stir in chopped cookies.
Spread tops of cupcakes with cream cheese frosting. Top with mini Oreo cookies.