In large bowl, sift together flour, sugar and salt. In sauce pan, over medium-high heat, heat water, 1/2 C (1 stick) margarine, oil and 1/4 C cocoa to a boil, stirring constantly; pour into flour mixture, stirring until smooth. Pour into greased and floured 13X9x2 inch baking pan. Bake at 350 degrees for 35 minutes or until toothpick inserted comes out clean. Cool completely on wire rack.
In sauce pan, over medium-high heat, heat milk and remaining Parkay margarine and cocoa to a boil. Remove from heat; stir in powdered sugar and remaining vanilla until smooth. Immediately pour over cooled cake. Cool completely. Cut into squares to serve.
In sauce pan, over medium-high heat, heat milk and remaining Parkay margarine and cocoa to a boil. Remove from heat; stir in powdered sugar and remaining vanilla until smooth. Immediately pour over cooled cake. Cool completely. Cut into squares to serve.
