For the crust:
- 1Stir the butter, oil, sugar, and salt together in a medium bowl until evenly combined. Add the measured flour and stir until a soft dough forms.
- 2Sprinkle the dough in small clumps over the bottom of a 9-1/2-inch deep-dish pie plate. Using a measuring cup or your fingers, evenly press the dough into the bottom and up the sides of the plate (flour the cup or your fingers occasionally to prevent sticking). Cover with plastic wrap and chill in the refrigerator for at least 30 minutes.
For the pie:
- 1Heat the oven to 350°F and arrange a rack in the lower third. Place a baking sheet on the rack while the oven is heating.
- 2Place all of the ingredients except the whipped cream in a large bowl and whisk until smooth and combined. Pour into the chilled pie crust.
- 3Place the pie on the hot baking sheet and bake until the top starts to brown and the filling is set but still jiggles slightly in the center, about 50 minutes. Remove from the oven to a wire rack and let cool completely before serving. Top slices of the pie with whipped cream, if desired.
Make-ahead note: This pumpkin pie can be made and refrigerated up to 1 day in advance. Let it come to room temperature before serving.