Sift flour, salt, soda, and cinnamon. Pour oil in mixing bowl. Add sugar and beat well. Add 1 egg at a time and beat well. Blend vanilla and sifted dry ingredients. Blend in remaining ingredients. Pour into greased 9x13-inch pan and bake at 350 degrees for 1 hour. Watch cake. Frost cake. For frosting: Cream together butter and cream cheese. Add vanilla and powdered sugar. Blend and beat until light and fluffy.