Buttermilk Sweet Potato Pie

Name: Buttermilk Sweet Potato Pie
Ingredients: 1 recipe All Buttah Pie Crust (https://food52.com/recipes...); 1 egg white (35 g); 2 1/2 cups mashed sweet potatoes (549 g); 6 tablespoons unsalted butter, melted (85 g); 2/3 cup buttermilk (163 g); 2 eggs (114 g); 1 egg yolk (21 g); 1 teaspoon vanilla extract (5 g); 3/4 cup granulated sugar (150 g); 1/2 cup dark brown sugar (106 g); 2 teaspoons ground cinnamon (6 g); 1 teaspoon ground ginger (3 g); 1/2 teaspoon ground allspice (2 g); 1/4 teaspoon ground nutmeg (1 g)