Preheat oven to 350 and prepare a 9x13 pan.
In mixer, combine oil, sugar, and vanilla until fully incorporated. (usually about 2 min on med speed)
In a separate bowl, sift together flour, cocoa, baking soda, and salt. With mixer on low, add flour mixture to sugar mixture and mix until just combined.
Remove bowl from stand and fold in zucchini by hand.
Spread brownie mixture into pan and bake for 25-30 minutes.