Top and bottom "crust" * 1 cup flour * 3/4 cup oatmeal (uncooked) * 1 cup brown sugar (packed) * 1/2 cup butter, (melted) Filling * 3/4 cup Sugar * 1-1/2 Tbls flour * 1/4 teas nutmeg * 1 Tbls butter (softened) * 1 egg (beaten) * 2 cups rhubarb (cut into 1/2" pieces)