Preheat oven to 425°F (218°C). Line two large baking sheets with parchment paper or silicone baking mats. Set aside.

Line a colander or large bowl with a few paper towels or a clean, thin kitchen towel. (You can also use cheesecloth for this step.) Place the shredded zucchini inside. Add 1/2 teaspoon salt, and gently mix together. Top with another paper towel and press down so the towels begin absorbing some liquid. Let sit for 10 minutes. Lift everything up using the bottom towel and, over the sink, wring/squeeze out as much liquid as you can. The goal is to remove as much moisture from the zucchini as possible. Give your hands a break if needed, then return to squeezing out more liquid. You will be amazed how much liquid you wring out! You’ll have about 1/2 cup of shredded zucchini to use in the dough. A little more or less is fine.

Place the flour, remaining 1/2 teaspoon salt, baking powder, baking soda, garlic powder, pepper, and parmesan cheese together in a large bowl or in a large food processor. Whisk or pulse until combined. Add the cubed butter and cut into the dry ingredients with a pastry cutter or 2 forks, or by pulsing several times in the processor. Cut/pulse until coarse crumbs form. Do not over-mix. If you used a food processor, pour the mixture into a large bowl.

Fold in the basil, parsley, and zucchini. Make a well in the center of the mixture. Pour 1 cup (240ml) buttermilk on top. Fold everything together with a large spoon or spatula until it comes together in one shaggy-looking ball. Avoid overworking the dough as best you can. Add a sprinkle of flour if dough seems too wet.

Divide the dough into 12 equal portions, about 4 Tablespoons of dough each. If you want to be precise, each should weigh about 65 grams. Shape into a ball as best you can and arrange 6 biscuits on each prepared baking sheet. Brush each evenly with remaining buttermilk. If desired, sprinkle each lightly with flaky sea salt.

Bake for 19–21 minutes or until the tops are golden brown. For a more accurate test, the biscuits are done when an instant-read thermometer inserted into the center registers 195–200°F (90–93°C).

Remove from the oven and enjoy warm. Cover leftovers tightly and store at room temperature or in the refrigerator for up to 5 days.