Rhubarb Pie recipes don't come much easier than this! Start with a refrigerated piecrust, then pour in a homemade four-ingredient fresh rhubarb filling. Since you can make this dessert with fresh or frozen stalks, you can make this rhubarb recipe any season of the year.
Preheat oven to 375 degree F. For filling, in a large bowl stir together sugar, flour, and cinnamon; stir in undrained rhubarb.
Line a 9-inch pie plate with pastry; trim. Transfer filling to pastry. Trim bottom pastry to edge of plate. Cut slits in remaining pastry; place on filling and seal. Crimp edge as desired. If desired, brush with milk; sprinkle with sugar.
Cover edge of plate with foil. Bake for 25 minutes; remove foil. Bake for 20 to 30 minutes more or until filling is bubbly in center and pastry is golden. Cool on a wire rack. Makes 8 servings.