1. Mix flour and salt in bowl. With pastry blender or finger-tips, rub butter and shortening into flour mixture until texture of coarse meal. Gradually add water, tossing with fork, until mixture begins to mass together. Shape into ball. Flatten into disk. Cover with plastic wrap. Refrigerate until well chilled, about 30 minutes. Roll dough out for single piecrust pie to 12-inch circle; line 9-inch pie pan. Make standup edge; crimp. Chill while making topping and filling.Crumb Topping:
2. Mix sugar and flour in bowl; stir in butter. Set aside for 5 minutes. Use fingertips to break the mixture into 1/4- to 1/2-inch crumbs.
3. Position oven rack in lowest level of oven. Heat oven to 400 degrees F.Filling:
4. Peel, halve and core apples. Cut the apples into 1/2-inch dice. Place the diced apples in a bowl; add the sugar, flour, ground cinnamon and grated lemon zest; toss well to combine.
5. Spoon the filling in the dough-lined pan, mounding it slightly in the center. Dot the filling with pieces of butter; sprinkle the crumb topping over filling to cover.
6. Place pie in the 400 degrees F oven and immediately lower the temperature to 375 degrees F. Bake the pie for about 40 minutes or until the crust and crumb topping are baked through and a deep golden brown and the filling is gently bubbling.
7. Place the pie on a wire rack to cool. Cut the pie into wedges and serve alone or with a scoop of ice cream or slices of sharp cheddar cheese, if desired.