Brown Sugar Sweet Potato Pie

Name: Brown Sugar Sweet Potato Pie
Prep time: 3 h 30 min
Cook time: 1 h
Total time: 4 h 30 min
Cuisine: American
Ingredients: 1 unbaked Flaky Pie Crust (what I used) or All Butter Pie Crust*; egg wash: 1 large egg beaten with 1 Tablespoon (15ml) milk or heavy cream; 1 lb sweet potatoes (about 2 medium); 6 Tablespoons (85g) unsalted butter, softened to room temperature; 1 cup (200g) packed light or dark brown sugar (I prefer dark); 1/2 (120ml) cup heavy cream; 2 large eggs; 2 Tablespoons (15g) all-purpose flour; 1 teaspoon pure vanilla extract; 1 teaspoon ground cinnamon; 1/2 teaspoon ground nutmeg; 1/4 teaspoon ground cloves; 1/4 teaspoon ground ginger; 1/8 teaspoon salt; optional for serving: whipped cream