Step 1 Whisk flour with salt until combined; cut in butter with a pastry blender or your fingertips until mixture resembles coarse meal. Using a fork, whisk egg yolk with water and stir into flour mixture until dough comes together, adding up to 1 tbsp (15 mL) more water if needed.
Step 2 Shape into ball and flatten into disk; wrap with plastic wrap and refrigerate for at least 1 hour or up to 2 days.
Step 3 Preheat oven to 400°F (200°C). On lightly floured surface, roll out pastry into 12-inch (30 cm) round, about 1/4-inch (5 mm) thick. Fit into 9-inch (23 cm) pie plate, pressing into bottom and sides; trim and discard excess pastry. Press edge with fork or flute with fingers. Refrigerate for 30 minutes.
Step 4 Prick bottom of pastry with fork. Line with foil or parchment paper; fill with pie weights. Bake in bottom third of oven for 20 minutes. Remove foil and weights; bake for about 5 minutes or until crisp and lightly golden. Let cool completely.
Step 1 Preheat oven to 350°F (180°C). Whisk together pumpkin purée, 3/4 cup (175 mL) cream, brown sugar, eggs, maple syrup, vanilla, cinnamon, ginger, cloves, nutmeg, salt, and cayenne (if using). Pour filling into pie shell. Bake for 55 to 65 minutes or until filling is set around edges but still jiggles slightly in centre. Transfer to rack; let cool completely.
Step 2 To serve, whip remaining cream with electric mixer until stiff peaks form. Stir in icing sugar. Serve each piece of pie with dollop of whipped cream.