Pumpkin Cream Pie with Sesame Shortbread Crust

1. Make the sesame shortbread crust:
Preheat oven to 350.
Lightly butter or grease a 9 or 10” springform cake pan.]
To the bowl of a food processor, add ¼ cup sesame seeds and ⅓ cup sugar. Pulse to combine and break down the sesame. Add 1 stick of cold butter (cut into 1” pieces). Pulse to combine until the butter becomes pebbly.
Add 1 cup flour and 1 teaspoon salt. Continue to process until a dough forms and starts to clump together when pressed between your hands, about 1 minute.
Transfer the dough (in a ball) to the greased cake pan. Place a piece of parchment right on top of the dough to prevent sticking, and use a flat-bottomed mug or measuring cup to press the dough out into the pan, until it meets the edges evenly all around. This will take some strength and pressing; be patient! You want one even layer of shortbread that meets the edges of the cake pan.
Remove the parchment. Prick all over with a fork. Bake until golden brown and no longer greasy or wet, 25-30 minutes. Let cool to room temperature. (Note: this step can be done up to 2 days in advance, keep covered at room temperature).
2. Make the pumpkin filling:
In either a large bowl or the bowl of the food processor, combine 5 large eggs, pulsing or whisking to blend. Add a 29 ounce can ( 3 ½ cups) pumpkin puree, 1 cup heavy cream, ½ cup granulated sugar, ⅔ cup sweetened condensed milk, 2 tablespoons molasses, 1 tablespoon plus 1 teaspoon Chinese five spice, 1 teaspoon ground ginger, 2 teaspoons kosher salt, and 1½ teaspoons vanilla extract. Whisk or blitz until very smooth.
Once the shortbread crust is no longer hot, pour the custard into the prepared pan. Tap once or twice on the counter to remove any air bubbles.
Place the cake pan on a rimmed baking sheet and return to the oven. Immediately reduce the oven temperature to 325. Cook until the pumpkin custard has just set and seems firm except for a slight jiggle in the center, about 1 hour 15  to 1 hour 25 minutes. Remove from oven and let cool to room temperature before proceeding with the whipped topping.
3. Make the whipped sour cream:
In the bowl of a stand mixer, or in a large bowl if using a hand mixer, combine 2 cups heavy whipping cream, ⅔ cup sour cream, 3 tablespoons sugar, 1 teaspoon vanilla extract, and a few pinches of salt. Beat until medium peaks form–the cream should not look grainy or overwhipped, but should also not be so loose that it will slump down off the pie.
Once the pumpkin custard has cooled to the touch, release the sides of the pan to remove. Cut a large piece of parchment in half lengthwise. Wrap the outsides of the pie with the two pieces of parchment (they will overlap some), such that there is now a tall parchment barrier rising above the level of the pie. Re-attach the springform sides. This will create a nice firm barrier for the whipped cream.
Dollop the whipped cream on top of the pumpkin custard and use a spatula to smooth it out, and spread it all the way to the edges of the parchment.
Chill, for at least 2 hours, and up to overnight, to set the whipped cream and the custard.
Before serving, remove the sides of the pan, and peel away the parchment paper. Garnish with more toasted sesame seeds and slice into wedges with a clean knife.