Preheat the oven to 325F degrees. Grease and flour a 9x5 inch loaf pan, or line with parchment paper.
In a medium bowl whisk together the flour, cinnamon, baking soda, baking powder & salt.
Whisk together the oil, sugars, eggs & vanilla extract in a separate bowl.
Stir the sour cream into the wet ingredients.
Gently fold the flour mixture into the wet ingredients using a rubber spatula or wooden spoon.
Pat the zucchini dry using a paper towel or clean tea towel to remove any excess water.
Stir in the grated zucchini and chocolate chips.
Pour the batter into the prepared pan and bake for 50-60 minutes, or until an inserted toothpick comes out clean.*
*Oven times will vary. If you notice the top getting too brown but the inside isn't done baking yet, tent a piece of aluminum foil over top of the pan and continue baking.
**Store leftovers in an airtight container at room temperature for up to 3 days. Loaf can be wrapped tightly and frozen for up to 2 months. Thaw in the fridge.