sift together flour, 1 c. sugarbak. powder and salt in a small bowl. Make a well in center, add oil, egg yolks. water, lemon rind& juice.beat@ high 5 min or till smooth~ beat egg whites and cream of tarter @ room temp; add remaining sugar2T @ a time, 4 min. to soft peak, slowly pour yolk mixture in steady stream over entire surface of mixture, fold together gently, pour into greased tube pan; bake at 350 for 1 hour, invert and cool.
(Frosting)Cream butter and sugar; add remaining ingd., beat till smooth. Spread over completely cooled cake