Sweet Potato Pie with Candied Pecans and Coconut

Name: Sweet Potato Pie with Candied Pecans and Coconut
Ingredients: 1 1/4 cups all-purpose flour, plus more for rolling; 1 teaspoon granulated sugar; 1/2 teaspoon kosher salt; 1/4 teaspoon baking powder; 8 tablespoons (1 stick) cold unsalted butter, cut into small pieces; 3 to 4 tablespoons ice water; 1 1/2 pounds garnet yams or sweet potatoes (about 3 medium); 3/4 cup heavy cream; 2/3 cup packed light brown sugar; 1 teaspoon pure vanilla extract; 1/2 teaspoon ground allspice; 1/2 teaspoon ground ginger; 1/4 teaspoon kosher salt; 2 large eggs, lightly beaten; 2 tablespoons unsalted butter; 2 tablespoons packed light brown sugar; 1/2 teaspoon pure vanilla extract; Pinch kosher salt; 1 cup pecans, coarsely chopped; 1/2 cup sweetened flaked coconut; Whipped cream, for serving, optional