1. Prepare and roll out pastry for double-crust pie. Line a 9-inch pie plate with half of the pastry. Set aside.
2. For filling, in a large bowl, stir together the 1/3 cup sugar, the cornstarch, and the salt. Add the apples and gently toss until coated.
3. In a small bowl, stir together maple syrup, whipping cream, and vanilla. Pour over apple mixture. Fold until combined. Transfer to the pastry-lined pie plate. Trim pastry to 1/2 inch beyond edge of pie plate.
4. Roll out remaining pastry and cut into 1/2-inch-wide strips. (Or roll out second portion of pastry to form a top crust; cut slits.) Weave strips over filling for lattice crust. Press ends of strips into crust rim. Fold bottom pastry over strips; seal and crimp edge. Brush pastry with milk and sprinkle with sugar. To prevent overbrowning, cover edge of pie with foil. If you like, place the pie on a baking sheet to catch drips.
5. Bake the pie in a 375 degree F oven for 25 minutes. Remove the foil. Bake the pie for about 30 minutes more or until the top is golden. Serve warm or cool. Makes 8 servings.