Preheat oven to 350° Fahrenheit and line an 9x9-inch baking pan with parchment paper.
Wrap the zucchini in a dish cloth and squeeze to release as much excess moisture from the zucchini as possible, then transfer the shredded zucchini to a large bowl.
Add in the maple syrup, olive oil, large egg, and vanilla extract, then mix until everything is fully combined.
Next, add in the oat flour or all purpose flour, unsweetened cocoa powder, and baking soda. Mix again until the dry ingredients are fully incorporated into the brownie batter.
Fold the chocolate chips into the batter, then transfer the batter to your prepared baking pan. Bake for 30-35 minutes, or until the brownies are just set in the middle them remove from the oven and let cool completely before slicing into squares.