Preheat the oven to 400 °F. Adjust the oven rack to the middle position, and place a rimmed baking sheet on the rack.
Whisk cream, milk, eggs, yolks, and vanilla together in medium bowl, and set aside.
Combine pumpkin puree, yams, sugar, maple syrup, ginger, cinnamon, nutmeg, and salt in a large heavy-bottomed saucepan; bring to a sputtering simmer over medium heat, 5 to 7 minutes. Continue to simmer pumpkin mixture, stirring constantly and mashing yams against the sides of the saucepan, until thick and shiny, 10 to 15 minutes.
Remove the pan from the heat and whisk in the cream mixture until fully incorporated. Strain mixture through a fine-mesh strainer set over a large bowl. Using the back of a ladle or spatula, press solids through the strainer. Re-whisk the mixture.
Roll out the pie crust into a 12-inch circle. Place the pie crust on the pie plate and trim the overhang to 1/2 inch beyond the lip of the plate. Tuck the overhang over itself and flute the dough evenly around the plate.
Place a pie crust on the pie plate and carefully place the plate on the preheated baking sheet. Pour the filling into the pie crust, and bake for 10 minutes at 400 °F. Without taking the pie out of the oven, reduce the heat to 350 °F and continue baking until the edges of the pie are set (instant-read thermometer inserted in center registers 175 °F), 20 to 35 minutes longer. The center 2 inches of the pie should look firm but jiggles slightly; the pie finishes cooking with residual heat.
Transfer to a wire rack and cool to room temperature and not in the refrigerator to ensure that the filling sets for about 4 hours. Cut into wedges and serve at room temperature or chilled with whipped cream.
Blind Baked Pie Crust method (optional)
Preheat the oven to 350 °F and place a rimmed baking sheet on the oven rack centered in the oven.
Roll out the pie crust into a 12-inch circle. Place the pie crust on the pie plate and trim the overhang to 1/2 inch beyond the lip of the plate. Tuck the overhang over itself and flute the dough evenly around the plate. Cover the crust lightly and chill for 30 minutes in the refrigerator.
Line the chilled pie shell with a double layer of aluminum foil. Don't cover the edges of the crust. Fill with pie weights. Bake on the preheated baking sheet until the edges start to turn golden, 25 to 30 minutes, rotating the sheet halfway through baking.
Remove the foil and weights, rotate the sheet, and continue to bake the crust until golden brown and crisp, 10 to 15 minutes.
Increase the oven temperature to 400 °F. Fill the warm pie crust with the filling and bake for 10 minutes.
Without taking the pie out of the oven, reduce the heat to 350 °F and continue baking until the edges of the pie are set (instant-read thermometer inserted in center registers 175 °F, 20 to 35 minutes longer, rotating the sheet halfway through baking.
Cool the pie completely on a cooling rack, for about 4 hours. Serve.
Notes
This recipe was adapted from American Test Kitchen and Life Currents blog.
This recipe was calculated using the exact brands and measurements I used to make this recipe. If you are following a strict diet please note changing anything will cause the nutritional info to change. My calculations are intended as a guide only.