Preheat oven to 375°F. Line a sheet pan with parchment paper.
In the bowl of an electric mixer, beat the butter, sugar, and brown sugar until light and creamy, 3-5 minutes. Stop to scrape down then bowl once or twice.
Add the egg, vanilla, and zucchini, beating after each and scraping down the bowl at least once.
Add the flour, baking soda, salt and cinnamon and mix until almost combined. Add the chocolate chips and walnuts and mix briefly until incorporated.
Portion equally (I use a #40 1½ Tbsp scoop) and roll into rounds. Space evenly about 4 inches apart on prepared sheet pan.
Bake for 9-11 minutes until edges are golden and top is set but not at all browned.
Let cool on the sheet pan for 5 minutes, then transfer to a wire rack to cool completely.
