Preheat the oven to 350°F. Coat a 9-by-5-inch loaf pan with cooking spray or line it with parchment paper.
Use a box grater to grate the zucchini (no need to peel it first). Scrape the zucchini onto a couple of layers of paper towels. Top with another layer of paper towels and press lightly to blot. Let it stand while you pull together the remaining ingredients.
Whisk together flours, baking powder, cardamom, baking soda, and salt in a large bowl, creating a well in the center of the dry ingredients. In a medium bowl, whisk together sugar, oil, tahini, vanilla, and eggs until well combined. Using a rubber spatula, fold in zucchini. Pour into the center of dry ingredients and stir just until combined. Stir in raisins. Scrape batter into prepared pan. Bake for 60 minutes or until a toothpick inserted in the center comes out clean.
Cool in pan for 5 minutes. Remove the loaf from the pan (and here’s where using parchment paper makes it easy to just lift out) and cool completely on a wire rack.