How to Make It
Preheat oven to 400°F. Line frozen pie shell with parchment paper, and fill with pie weights. Bake until crust edges are lightly browned, 16 to 18 minutes. Remove paper and weights; prick bottom of crust several times with a fork. Return to oven; bake until bottom is lightly browned, 4 to 6 minutes. Transfer to a wire rack to cool completely, about 30 minutes. Reduce oven temperature to 350°F.
Whisk together pumpkin, ginger, orange zest, vanilla, salt, cinnamon, and nutmeg in a large bowl; set aside.
Stir together granulated sugar and 3 tablespoons water in a small saucepan. Cook over medium, stirring constantly, until sugar melts, about 3 minutes. Increase heat to medium-high; cook, swirling saucepan often, until mixture is rich caramel in color, 6 to 7 minutes; remove from heat. Gradually add warm cream to sugar mixture, whisking constantly. (Mixture will bubble up.) Whisk in brown sugar and butter until smooth and incorporated.
Whisk warm caramel mixture into pumpkin mixture until combined. Whisk in eggs, 1 at a time, until incorporated. Pour mixture into pie shell; smooth top with an offset spatula. Bake at 350°F until filling is set and crust is golden, about 1 hour. Turn oven off, and crack open oven door; let pie stand in oven 15 minutes. Transfer pie to a wire rack to cool completely, about 4 hours. Garnish with candied pepitas.