Preheat the oven to 350° F (180º C). Line a 13x9-in baking pan with parchment paper and lightly grease with baking spray.
In a large bowl, whisk the flour, sugar, cocoa, baking powder, baking soda, and salt. Set aside.
In a small mixing bowl, whisk evaporated milk, vinegar, oil, and vanilla until blended. Add to flour mixture; stir just until moistened. Stir in zucchini and chocolate chip; mix until just combined.
Transfer batter to prepared baking pan.
Bake 25-30 minutes, or until the center of the brownies in the pan no longer jiggles and is just set to the touch. If testing with a toothpick, the toothpick should come out dirty for fudge-textured brownies. If there is wet batter on the toothpick, they need more time. Take them out of the oven.
Cool completely in the pan on a wire rack before cutting.
Evaporated milk: If you don't have evaporated milk, you can make your own. Check out how to make evaporated milk at home. This recipe to make your own evaporated milk will work well also with soy, rice, oat, or almond milk instead. If evaporated milk is not available and making your own is not an option, you can use regular milk, in that case, I recommend substituting half of the granulated sugar for brown sugar. Store cut brownie squares in an airtight container at room temperature; they're best eaten within 1 to 2 days. It is best to keep the brownies in the fridge in very hot weather and remove them about an hour before you want to eat them.Freeze: you can freeze the whole pan of uncut brownies well wrapped in plastic and foil for up to 3 months. If you wish to freeze cut brownies individually, wrap each one in plastic wrap and foil and freeze in airtight containers for up to 1 month.To defrost frozen brownies, remove the tin from the freezer, unwrap it and leave it at room temperature for 2-3 hours. If you defrost a whole tray of uncut brownies, I suggest cutting them when they are still partially frozen.Extra Tips:
Peeling the zucchini is not necessary.
You can use a grater to shred your zucchini or use the “shred” setting on your food processor.
Lightly blot the sheered zucchini to remove the extra water.
You can half the recipe and bake it in a square baking pan.
Let the brownies cool completely in the pan before cutting into squares.
If you're making this recipe, please read the whole post content to get lots of tips, tricks, variations, frequently asked questions, and step-by-step photos.★ Did you make this recipe? Don't forget to give it a star rating below!Please note that nutritional information is a rough estimate, and it can vary depending on the products used.