Preheat oven to 350 degrees. Generously grease a 13x9 inch baking pan. Set aside.
In a large bowl mix together flour, sugar, brown sugar, salt, baking soda, baking powder and cinnamon.
3 cups all-purpose flour, 1 cup granulated sugar, 1 cup light brown sugar, 1 teaspoon salt, 1 1/2 teaspoon baking soda, 1 teaspoon baking powder, 2 teaspoon cinnamon
In a separate bowl mix together vanilla, eggs and oil. Add flour mixture and fold until mostly combined. Add zucchini (do not drain), and mix until fully incorporated. Fold in chocolate chips.
1 teaspoon vanilla extract, 3 large eggs, 3/4 cup oil, 3 cups zucchini, 2 cups semi-sweet chocolate chips
Pour into prepared pan. Bake for 35-40 minutes until a tester comes out clean.
Cool completely.
Meanwhile prepare the frosting. Mix together all of the ingredients until well blended. Beat until fluffy. Adjust the milk and sugar as necessary to get a spreadable consistency.
1/2 cup butter, 1 teaspoon vanilla extract, 1/3 cup milk, 1/2 cup Nutella, 2 - 3 cups powdered Sugar