Stir cocoa and baking soda in mixing bowl. Blend in 1/3 cup vegetable oil. Add boiling water. Stir until mixture thickens. Stir in sugar, eggs, and remaining 1/3 cup oil. Stir until smooth. Add flour, vanilla and salt. Blend completely. Pour into lightly greased 13 x 9-inch pan. Bake at 350° for 35 – 40 minutes.