Find recipes for Rhubarb Torte and other Course recipes. Get all the best recipes at . Recipe directions: Combine first six ingredients with a fork until crumbly. Press into a greased 13-in. x 9-in. baking pan. Combine filling ingredients; mix well. Pour over crust. Bake at 350&deg; for 50-60 minutes. In a bowl, beat egg whites until stiff. Gradually add sugar and vanilla, beating well. Spread over hot filling. Return to the oven for 10-15 minutes or until lightly browned.