Sweet Potato Buttermilk Pie

Sweet Potato Buttermilk Pie 2 medium sweet potatoes 1/2 pkg refrigerated pie crusts (15 oz package) 4 Tbsp butter, unsalted melted 2 Tbsp fresh lemon juice 1/2 tsp freshly grated nutmeg 1/2 tsp ground cinnamon 1/2 tsp kosher salt 3 large eggs, separated 1 1/2 c sugar 2 Tbsp all-purpose flour 3/4 c buttermilk Bake potatoes at 400 degrees for 1 hour or until tender. Cool 10 minutes. Increase oven temperature to 450 degrees. Fit pie crust into a 9-inch pie plate. Fold edges under and crimp. Prick bottom and sides of pie crust with a fork. Bake at 450 for 9-11 minutes or until lightly browned. Reduce oven temperature to 375. Cut potatoes in half lengthwise. Scoop out sweet potatoes into a medium bowl. Mash until smooth. Stir in butter and next 4 ingredients until well combined. Whisk egg yolks until thick and pale. Add sugar and whisk 1 1/2 minutes or until lemon-yellow color. Stir egg yolk mixture into sweet potato mixture until well blended. Add flour 1 tsp at a time; stirring until blended after each addition. Add buttermilk and stir until combined. Whisk egg whites in a bowl until soft peaks form. Gently fold into sweet potato mixture until blended. Spoon sweet potato mixture into pie crust. Bake at 375 for 35-40 minutes or until center is set. Let cool on a wire rack for 1 1/2 hours or until completely cool. Or, cover with plastic wrap and chill for 8 hours. Serve at room temperature. Serve with desired toppings.