Zucchini Brownies

Ingredients

• 1/2 cup vegetable oil
• 1 1/2 cups white sugar
• 2 teaspoons vanilla extract
• 2 cups all-purpose flour
• 1/2 cup unsweetened cocoa powder
• 1 1/2 teaspoons baking soda
• 1 teaspoon salt
• 2 cups grated zucchini
• 1/2 cup chopped walnuts or chocolate chips (optional)