Make the crust: Add all crust ingredients to the bowl of a large food processor. Pulse until dough comes together and forms a ball. Turn out onto plastic wrap, form into a disc, and refrigerate for 2 hours until firm.

Roll dough between two sheets of a slit 2-gallon zip-top bag to fit your pie plate. The dough is delicate - just patch any tears by pressing together.

Heat oven to 450°F with rack in center. Separate eggs. In a blender or large bowl, blend pumpkin puree, erythritol, 1/2 tsp salt, molasses, bourbon if using, spices, egg yolks, and cream until smooth.

In a clean bowl, whip egg whites until foaming. Add a pinch of salt, then gradually whip in 1 tablespoon of erythritol until shiny peaks form. Beat 1/4 of the whites thoroughly into pumpkin mixture, then gently fold in the rest.

Immediately ladle filling into the shell to just below the rim. Bake until rim of crust begins to turn gold, 10 to 15 minutes. Reduce heat to 375°F and bake another 25 to 30 minutes until a tester 2 inches from the rim comes out clean. Cover crust edges with foil if browning too fast.

Turn oven off. Leave door ajar (prop with a wooden spoon) and let sit 20 to 30 minutes as the oven cools - this prevents the filling from turning watery. Serve warm or refrigerate tightly wrapped up to 2 days. Bring to room temperature before serving.