Maple Pecan Pie

Name: Maple Pecan Pie
Cuisine: American, Southern
Ingredients: 1 prepared pie crust (store-bought or homemade); 6 tablespoons unsalted butter, melted and cooled slightly; ½ cup packed dark brown sugar; 1 tablespoon all-purpose flour; 2 teaspoons pure vanilla extract; 1 teaspoon kosher salt; 3 large eggs, at room temperature; 1 cup pure maple syrup; 2 cups pecans; Flaky salt, optional, for garnish; Whipped cream, optional, for serving