Preheat the oven to 350 degrees and spray an 8x8 baking dish with non-stick cooking spray.
Cream together the softened butter, sugar and eggs and shredded zucchini.
Fold in the flour, baking soda, cinnamon, and salt.
Add in the chocolate chips.
Pour the mixture into the baking dish and sprinkle extra chocolate chips on top.
Bake 30-35 minutes or until a toothpick comes out clean in the middle.
Let cool and cut into pieces.