Preheat oven to 350 degrees
Shred zucchini and pat dry using paper towels (see notes above)
In a medium bowl, whisk together 2 cups of all purpose flour, 1 teaspoon of cinnamon, 1/2 teaspoon of all spice, 1/4 teaspoon of ginger, 1/4 teaspoon of nutmeg, 1/2 teaspoon of salt, 1 teaspoon of baking powder and 1 teaspoon of baking soda and set aside
In a large bowl, whisk 8 tablespoons of melted butter with 1/4 cup of vegetable oil, 1/4 cup of sour cream, 2/3 cup of brown sugar, 1/3 cup of granulated sugar, 2 large eggs and 2 teaspoons of vanilla extract until creamy
Add the dry ingredients in with the wet ingredients and mix until fully combined
Add the shredded zucchini and mix until evenly distributed
If you are adding the chocolate chips and walnuts, fold them into the batter
Grease a 9' loaf pan and line with parchment paper
Transfer the batter into the pan and bake at 350 degrees for 60-70 minutes or until a toothpick will come out of the middle of the loaf fairly clean
Transfer the loaf pan onto a cooling rack for about 10 minutes and then transfer the loaf out of the pan and directly onto the cooling rack to continue cooling
Enjoy warm with butter or at room temperature