Preheat oven to 375 degrees F with rack in center position. Roll your prepared dough disk to a 12-13 inch circle. Fold the dough into quarters and gently fit it into a 9-inch pie plate without stretching the dough. Trim dough to a 1/2-inch overhang and tuck to make a double-thick edge flush with the circumference of the plate. Flute or crimp the tucked edge. Refrigerate (30 minutes) or freeze (15 minutes) until dough is chilled and firm.
Line pie plate with two large squares of parchment paper or foil and fill with pie weights. Bake until edges are light golden, about 18 minutes. Gather edges of parchment or foil and remove weights (be careful; they'll be very hot) and continue baking crust until the bottom starts to look opaque, about 3-5 minutes. Let crust cool completely on a wire rack.
Make and bake the pie
Reduce oven temperature to 350 degrees F.
While the crust is baking, pierce the sweet potatoes all over with a fork to create steam holes. Place potatoes on a microwave-safe plate and cook on HIGH for 15 minutes, or until fully cooked. Turn over every 5 minutes, checking for doneness. When potatoes are soft, immediately cut in half lengthwise and let sit at room temperature until cool enough to handle.
While potatoes are cooling, place butter in a small skillet. Melt, over medium heat, until foaming subsides and solids are a light golden brown (watch carefully!). Remove from heat, let stand a few minutes, and then stir in cinnamon and nutmeg. Set aside.
Use a spoon to scoop sweet potatoes from their skins and transfer to the bowl of a food processor (discard skins). Add light brown sugar, salt, and browned butter/spice mixture. Process until smooth. Scrape bowl and add sour cream, whole eggs and yolks, vanilla, and bourbon. Process until fully combined.
Pour sweet potato mixture into the cooled pie crust. Bake until edges are firm but center still jiggles slightly, about 35 minutes. Center of pie should register 165 degrees on an instant-read thermometer. Watch carefully, as overcooked pies will be prone to cracking and will not have as silky a texture. Transfer pie to a wire rack to cool completely.
Optional: place marshmallow crème in a piping bag and decorate the top of the cooled pie just before serving. To toast, use a kitchen torch, or broil pie in the oven until marshmallow crème is golden brown. (If broiling, cover pie edges with a foil collar so they don't burn.) Slice and serve.
A topping of toasted homemade marshmallow crème is a sweet, fun, and impressive way to serve this silky Sweet Potato Pie. For best results, it should be piped and toasted just before serving. For an alternative presentation, pipe the pie with lightly-sweetened whipped cream, or serve slices with a dollop on the side.