Heat oven to 425 degrees. Prepare piecrust according to package directions for two-crust pie using 9-inch pie pan. In large bowl, combine pears, cranberries, 1 cup sugar, cornstarch and 3 tablespoons juice; mix lightly. Spoon into piecrust-lined pan; dot with margarine. Unfold second crust; using 2-inch cookie cutter, cut out desired chapes in several places. Place crust over filling; flute. Brush underside of 2-inch cutouts with water and place on top of crust. Bake at 425 degrees for 40 to 50 minutes, or until golden brown. Cover edge of piecrust with strips of foil after 15 to 20 minutes of baking to prevent excessive browning. To make a glaze, blend confectioners' sugar and juice in a small bowl, adding enough juice for desired consistency. Drizzle over warm pie. Garnish as desired. Makes 8 servings.