Prepare brownie batter according to package; stir in vanilla and bittersweet chips. Spread onto the bottom and up the sides of a greased 9-inch pie plate. Bake at 350° for 35-40 minutes or until a toothpick inserted near the center comes out clean. Cool for 5 minutes. Gently press down center of crust if necessary. Cool completely on a wire rack. Drizzle caramel topping over crust; spread evenly with ice cream. Cover and freeze for 4 hours or until firm. Remove from the freezer 10 minutes before serving. Meanwhile, in a small bowl, beat cream, confectioners’ sugar and extract until stiff peaks form. Spread over ice cream; sprinkle with crushed peppermints.