Preheat your oven to 325°F. Lightly oil an 8x8 inch baking pan and line it with parchment paper, leaving some overhang on two sides so you can lift the brownies out later.

In a small bowl, whisk together the ground flaxseed and water. Let the mixture sit for 5 minutes until it becomes thick and gelatinous.

In a medium bowl, whisk the flour, sugar, cocoa powder, baking powder, and fine sea salt until everything is evenly distributed.

In a large bowl, whisk the melted coconut oil, vanilla, and prepared flax mixture together until smooth. Stir in the shredded zucchini until well coated.

Pour the dry ingredients into the zucchini mixture and fold with a spatula. The batter will look very thick and dry at first, so pause for 1 minute to let the zucchini release its moisture. Stir again until no dry streaks remain and the batter becomes smoother and wetter, then fold in the chocolate chips.

Transfer the batter into the prepared pan and smooth the top with a spatula. Scatter extra chocolate chips and a generous pinch of flaky sea salt over the surface. Bake for 45 to 50 minutes, or until the center is set and a toothpick inserted into the middle comes out clean or with just a few moist crumbs.

Let the brownies cool in the pan for at least 1 hour before lifting out and slicing into 16 squares. Cooling fully ensures cleaner edges and a fudgy texture.