Rhubarb pie, made with lemon zest, has a delightfully sweet-sour tang.
Preheat oven to 375 degrees, with rack in bottom third. Stir together rhubarb, granulated sugar, cornstarch, salt, and lemon zest and juice in a large bowl; set aside.
On a lightly floured surface, roll out 1 piece of dough to a 13-inch round, about 1/8 inch thick. Fit into a 9 1/2-inch deep-dish glass pie plate. Fill with rhubarb mixture, and dot with butter. Refrigerate.
On a lightly floured surface, roll out remaining dough to a 13-inch round. Drape over filling. Trim edge to 1 inch. Fold edge under, and crimp as desired. Make five 2 1/2- to 3-inch slits in crust to vent. Refrigerate 15 minutes.
Whisk cream and egg yolk in a small bowl. Brush over crust. Sprinkle with sanding sugar. Bake until bottom crust is golden and filling is bubbling vigorously, 1 hour 10 minutes to 1 hour 25 minutes. Cover with foil if browning too quickly. Let cool at least 4 hours.