3 c. rhubarb, partially peeled, cut in 1/4" pieces
3 tbsp. flour, well rounded
1 (9") unbaked pie shell
2 tbsp. thick dairy sour cream
1 c. sugar
3 eggs, separated

TOPPING:

1 1/2 c. old fashioned or quick cooking oats
1 c. brown sugar
1/4 c. butter
1/2 tsp. cinnamon

Place cut rhubarb in large mixing bowl; combine flour and sugar. Add to rhubarb, mix and let stand while preparing the crust. Using your favorite pastry recipe for a single crust pie, make a pie shell with a high fluted edge in order to hold all of the topping. Brush the bottom and sides of crust with egg white from separated egg (prevents crust from becoming soggy). Beat egg yolks and sour cream until thick; add to rhubarb mixture. Pour into pie shell. Combine topping ingredients; spread evenly over pie. Bake at 400 degrees for 10 minutes; reduce heat to 350 degrees and bake 50 minutes more.