Preheat the oven to 425°F.
Prepare your sourdough pie crust in a 9-inch pie plate. Refrigerate while preparing the filling.
In a large mixing bowl, whisk together the pumpkin purée, eggs, and maple syrup until smooth.
Add the heavy cream, vanilla extract, pumpkin pie spice, and salt. Whisk until completely combined.
Pour the filling into the prepared, unbaked pie crust.
Bake at 425°F for 15 minutes.
Without removing the pie from the oven, reduce the temperature to 350°F. Continue baking for approximately 40–60 minutes longer, checking for doneness as it approaches the lower end of the range.
The pie is done when the edges are set and the center still has a slight jiggle. If using an instant-read thermometer, look for approximately 175–180°F in the center.
Remove the pie from the oven and cool on a wire rack for approximately 2 hours.
Refrigerate for at least 4 hours, preferably overnight, before slicing and serving.