Prep the pan and oven: Heat the oven to 350°F (175°C).
Grease a 9-inch pie dish or 9-inch round baking dish with butter or nonstick spray.
Whisk the dry mix: In a large bowl, whisk sugar, brown sugar, cornstarch, cinnamon, ginger, nutmeg, cloves, and salt until no lumps remain.
Add the wet ingredients: Whisk in pumpkin puree, then beat in eggs one at a time. Add milk and vanilla, whisking until smooth and glossy.
Strain for silkiness (optional): For an ultra-smooth custard, pour the batter through a fine-mesh sieve into a pitcher or bowl.
Fill and tap: Pour the mixture into the pie dish. Tap the dish gently on the counter to pop any air bubbles.
Bake gently: Bake for 45–55 minutes, until the edges are set and the center wobbles slightly like Jell-O. Do not overbake.
Cool gradually: Turn off the oven, crack the door, and let the pie rest for 10 minutes.
Move to a rack and cool to room temperature.
Chill to set: Refrigerate for at least 3 hours, or overnight, for clean slices and best flavor.
Serve: Slice with a warm knife. Add whipped cream or a dollop of Greek yogurt. Dust with cinnamon if you like.