Preheat oven to 350°F. Grease a 8x8 inch square pan with non-stick spray and line with parchment paper. Set aside.
In a large bowl, whisk together Pamela's Chocolate Brownie Mix, 1/4 teaspoon cinnamon, vegetable oil, water and egg. Fold in zucchini, chocolate chips and walnuts.
Pour brownie batter into prepared pan and spread into an even layer.
Sprinkle top of brownie batter with remaining cinnamon and granulated sugar. If you would like, you can add extra walnuts and dark chocolate chips on top too.
Bake for 20 to 22 minutes, until a toothpick inserted in the center comes out clean. Let cool completely.
Brownies are best if you let them rest for 24 hours before eating, but can absolutely be eaten as soon as they cool! Store brownies in an airtight container for up to 4 days.