Preheat oven to 425°F. Let refrigerated piecrust stand at room temperature according to package directions. Line a large baking sheet with parchment paper; set aside. In a large bowl combine granulated sugar and cinnamon. Add pear slices, pecans, and cranberries; toss to coat.
Place piecrust on prepared baking sheet. Spread mincemeat over crust to within 2 inches of edges. Mound pear mixture over mincemeat. Fold edges of pastry 2 inches up and over pear mixture, pleating edges as necessary. Brush folded edges lightly with milk; sprinkle with coarse sugar.
Bake 20 to 25 minutes or until crust is golden and pears are just tender. Serve warm. If desired, serve with vanilla ice cream.