Marbled Chocolate Zucchini Bread

Check 1/2 cup plus 2 teaspoons canola oil, plus more for the pan

Check 1 1/2 cups all-purpose flour (7 ounces)

Check 5 ounces semisweet chocolate, melted

Check 1 1/2 teaspoons cinnamon

Check 1 teaspoon salt

Check 1/2 teaspoon baking soda

Check 1/4 teaspoon baking powder

Check 1 cup sugar

Check 2 large eggs, lightly beaten

Check 1 1/2 teaspoons pure vanilla extract

Check 2 packed cups shredded zucchini (9 ounces)