Mix flour and salt. Cut in cold butter until crumbly with pea-sized pieces. Add ice water one tablespoon at a time until dough holds together. Shape into a disc, wrap, refrigerate at least 1 hour.
Preheat oven to 375 degrees Fahrenheit. Roll dough into a 12-inch circle and fit into a 9-inch deep dish pie dish. Crimp edges. Refrigerate 15 minutes.
Line crust with parchment and pie weights. Bake 10 minutes. Remove weights and parchment, prick bottom, bake 7 to 8 more minutes until just golden.
Whisk pumpkin, eggs, and brown sugar together. Add cornstarch, salt, and all spices including black pepper. Whisk in heavy cream and milk until smooth.
Pour filling into warm crust, three-quarters full. Bake 55 to 60 minutes. After 25 minutes, cover crust edges with foil. Pie is done when edges are set and centre jiggles gently.
Cool on wire rack at least 3 hours. Refrigerate overnight for best results.