Roll pastry on well-floured board into 12-inch circle. Brush off any excess flour. Transfer to 9-inch pie pan; trim to 1/2-inch overhang. Crimp to form stand-up edge. Prick bottom of dough all over with fork. Refrigerate at least 30 minutes.
Heat oven to 450°F. Line dough with aluminum foil; fill with dried beans or pie weights.
Bake in 450°F oven for 10 minutes. Reduce oven temperature to 350°F. Bake for 10 minutes. Remove foil and beans. Bake until crust is golden, about 15 minutes. Cool on rack.
Heat butter in large skillet. Add apples and sugar; cook, stirring, until apples are very tender and thickly glazed, 15 to 20 minutes. Cool to room temperature.
Heat milk in saucepan until bubbles appear around edge of pan. Whisk yolk, syrup, cornstarch and vanilla in bowl until smooth. Gradually whisk in milk. Return mixture to saucepan. Stir over low heat until thickened. Remove saucepan from heat; whisk for 1 minute.
Spoon apples into crust. Top with hot maple mixture; smooth top. Cool to room temperature. Refrigerate until custard is firm, about 1 hour.
Beat cream in bowl until soft peaks form. Beat in sugar and cinnamon until firm peaks form. To serve, decorate with whipped cream.
Stir together all-purpose flour and salt in medium-size bowl. Cut in butter and shortening, with a pastry blender until the mixture resembles coarse meal. Sprinkle water, 1 tablespoon at a time, over mixture, tossing lightly with fork after each addition until pastry is just moist enough to hold together. Divide pastry in half, shape each half into a disk. Wrap in plastic wrap. Chill for 1 hour or up to 2 days.