Preheat the oven to 350 F. Line a cupcake sheet with cupcake liners or spray with nonstick spray.
In a medium bowl, combine flour, baking soda, cinnamon, and salt and set aside.
In a separate large bowl, whisk together sugars, canola oil, egg and milk until smooth.
Shred zucchini into a fine texture with a box grater. With a cheesecloth or tea towel, squeeze out any excess water from the zucchini and add it into the wet mixture.
Gently add in flour mixture and stir until just combined. Do not over mix.
Gently fold in chopped walnuts and chocolate chips.
Scoop batter into prepared cupcake tin about ¾ of the way full. Top with a few more chocolate chips.
Bake muffins for 20-25 minutes, or until a toothpick inserted in the center comes out clean.