Preheat your oven to 350 degrees F. Line two baking sheets with parchment paper.

Grate the zucchini on the fine holes of a box grater. Wrap the grated zucchini in a clean kitchen towel and squeeze firmly over the sink, removing as much liquid as possible. You want the zucchini to feel nearly dry to the touch. Set it aside.

Before measuring your tahini, open the jar and stir it thoroughly from the bottom up until the oil and paste are fully blended. Separated tahini will make the dough too greasy or too stiff. Measure out 1/2 cup of the well-stirred tahini into a large mixing bowl.

Add the coconut sugar, egg, and vanilla to the tahini. Whisk everything together until the mixture is smooth and a little glossy, about 1 minute.

Stir in the squeezed zucchini using a rubber spatula.

Add the flour, baking soda, baking powder, salt, and cinnamon on top of the wet mixture. Stir until a soft dough forms and no dry streaks remain. The dough will be stickier than a standard butter cookie dough, and that is normal.

Scoop rounded tablespoons of dough onto the prepared baking sheets, spacing them about 2 inches apart. Flatten each ball slightly with your fingers or the bottom of a glass. Sprinkle a small pinch of flaky sea salt on top of each cookie.

Bake for 10 to 12 minutes, until the edges are set and the tops look dry but the centers still appear soft. They will firm up as they cool. Let the cookies rest on the baking sheet for 5 minutes before moving them to a wire rack.

Cool completely before storing or serving. The sesame flavor deepens a bit as the cookies sit, so they are actually even better the next day.