NOTE: You can use any type of milk chocolate candies in place of the M&Ms. ~-------------------------------------------------------------------------Beat margarine and brown sugar until light and fluffy. Add flour and walnuts, mix well. Reserve 1/2 cup crumb mixture; press remaining crumb mixture into bottom of 8-inch square pan. Bake at 350 degrees F. 10 mins. Combine cream cheese, granulated sugar and vanilla, mixing at medium speed on electric mixer until well blended. Add egg, mix well. Layer 1/2 cup candy over crust; top with cream cheese mixture. Combine remaining candy, chopped, and reserved crumb mixture; mix well. Sprinkle crumb mixture over cream cheese mixture. Bake at 350 degrees F., 20 minutes. Cool and cut in to 16 equal squares.