1. On a lightly floured surface, roll out dough to a 13-inch round about 1/8 inch thick. Brush off excess flour. Wrap the dough around the rolling pin, and lift it over a 9-inch pie plate. Line the pan with the dough, pressing it into the sides. Trim dough, leaving about 1/4 inch overhang all around; fold dough under to form a rim. Crimp edge with a fork. Cover with plastic wrap, and chill in refrigerator at least 30 minutes or up to 1 day.

2. Preheat oven to 375 degrees, with rack in center. Prick bottom of dough all over with a fork. Line with parchment paper, pressing into corners, and fill with pie weights or dried beans. Bake until edges begin to turn brown, 15 minutes. Remove pie weights, and bake 8 minutes more. Transfer to a wire rack to cool.

3. Combine sweet potatoes and butter in the bowl of an electric mixer fitted with the paddle attachment. Beat on medium speed until smooth. Add 1/2 cup brown sugar, maple syrup, bourbon (if using), vanilla, cinnamon, salt, and nutmeg. Mix until well combined. Add half-and-half, 1 egg, and the egg yolk; mix until smooth.

4. Sprinkle the remaining 3 tablespoons brown sugar and the chopped pecans evenly over bottom of prepared crust. Pour in filling. In a small bowl, combine remaining egg and cream; brush this egg wash evenly over edge of crust. Return to oven; bake until set, 30 to 40 minutes. Transfer to a wire rack to cool. Serve with bourbon whipped cream.