- 1/2 cup plus 2 teaspoons canola oil, plus more for the pan
- 1 1/2 cups all-purpose flour (7 ounces)
- 5 ounces semisweet chocolate, melted
- 1 1/2 teaspoons cinnamon
- 1 teaspoon salt
- 1/2 teaspoon baking soda
- 1/4 teaspoon baking powder
- 1 cup sugar
- 2 large eggs, lightly beaten
- 1 1/2 teaspoons pure vanilla extract
- 2 packed cups shredded zucchini (9 ounces)
- Heat oven to 350° F. Brush an 8½-by-4½-inch loaf pan with oil and dust with flour, tapping out the excess.
- Stir together the chocolate and 2 teaspoons of the canola oil. Set aside to cool to room temperature.
- Whisk together the flour, cinnamon, baking powder, baking soda, and ¾ teaspoon salt in a medium bowl; set aside.
- In a separate bowl, whisk together the remaining ½ cup canola oil, sugar, eggs, and vanilla. Stir in the zucchini. Add the wet ingredients to the dry ingredients and whisk vigorously to combine, about 1 minute.
- Transfer half the batter to the prepared pan. Pour half the chocolate into the pan. Repeat with the remaining batter and chocolate. Using a toothpick, swirl the chocolate and batter together to create a marbled pattern. Make sure to incorporate the batter at the bottom.
- Bake until a toothpick inserted in the center comes out clean, 60 to 70 minutes. Cool in the pan for 15 minutes. Transfer to a wire rack and let cool completely.