Preheat oven to 450 degrees F. Prepare and roll out Oat Pastry. Line 9-inch pie plate with pastry. Trim crust to 1/2-inch beyond pie plate. Flute edges as desired. Line with double thickness of foil. Bake 8 minutes. Remove foil and bake 6 minutes. Cool on wire rack. Reduce oven temperature to 350 degrees F.

For filling, in bowl combine pumpkin, pumpkin butter, and cinnamon. Add egg whites; beat lightly with fork to combine. Gradually add milk; stir just until combined.

Carefully pour filling into pastry shell, spreading to edges. To prevent overbrowning, cover edge of pie with foil. Bake 25 minutes. Remove foil. Bake 25 minutes more or until knife inserted near center comes out clean. Cool on wire rack. Cover and refrigerate within 2 hours. Serves 8.

In mixing bowl combine 1 cup all purpose flour, 1/3 cup quick-cooking rolled oats, and 1/2 teaspoon salt. Using pastry blender or two knives, cut in 1/4 cup shortening until pieces are pea-size. Sprinkle 1 tablespoon of cold water over part of flour mixture; gently toss with fork. Push moistened dough to side of bowl. Repeat, using 1 tablespoon water at a time, until all flour is moistened (4 to 5 tablespoons total). Form into a ball. On lightly floured surface, flatten dough. Roll from center to edge into a 12-inch circle.