In a double boiler, boil raisins and water for 10 minutes. Cool; drain if liquid remains.
In a large bowl combine shortening, oatmeal, flour, soda, brown sugar and nuts (if desired). Mix until crumbly and coarse. Put 1/2 of this mixture in a greased 9 x 13-inch pan and bake in 350 degrees oven for 7 minutes.
In a double boiler, place the egg yolks, 1 cup sugar, the sour cream and cornstarch and boil until thick, stirring constantly. Add raisins and vanilla. Spread the raisin-cream mixture over the baked crust. Sprinkle the remaining 1/2 flour-oatmeal mixture over egg yolk mixture and bake at 350 degrees for 30 minutes.
Recipe submitted by SLIM PICKINGS on 5/20/00