Chocolate Zucchini Cake

1 C vegetable oil
2 C sugar
3 eggs
2 1/2 C flour
1/2 tsp salt
2 C grated zucchini
1 tsp baking soda
1/4 tsp baking powder
1/2 C milk
3-1oz squares semisweet baking chocolate
1 Tbl vanilla

Combine oil, sugar and eggs. Sift dry ingredients and add to egg mixture. Add milk. Mix well. Melt baking chocolate in microwave (20 sec. at a time). Blend choc. and vanilla into batter. Stir in zucchini. Bake in greased 9 x 13 pan @ 350 degrees for 45 min. Cool and frost with Chocolate Butter Frosting.