Heat oil and chocolate in 8" square cake pan, in 350F oven for about 4 minutes.
Add water, sugar, egg, flour, salt, baking soda and vanilla.
Beat with fork until smooth, about 2 minutes.
Spread evenly in pan.
Sprinkle with chocolate chips and nuts.
Bake at 350F for 40 minutes, or until cake tester inserted in center comes out clean.