Heat your oven to 170°C (340°F). While it preheats, grease a loaf pan (approximately 8x4 inches or similar) generously with butter or oil, paying special attention to the corners and sides to ensure easy removal later. This gives you about 10-15 minutes for the remaining prep work while the oven reaches temperature.
In a medium bowl, whisk together the flour, baking powder, baking soda, cardamom, nutmeg, and salt until evenly combined—this helps distribute the leavening agents and spices throughout the batter for consistent flavor. In a separate small bowl, shred the zucchini using a box grater or food processor, then squeeze it firmly in a clean kitchen towel or cheesecloth to remove excess moisture; this prevents the bread from becoming soggy and dense.
In another medium bowl, whisk together the room-temperature egg, olive oil, date syrup, buttermilk, and vanilla essence until well combined and homogeneous. The room-temperature egg emulsifies better with the oil, creating a smoother batter. I like to whisk vigorously for about 30 seconds to ensure the oil and buttermilk are properly incorporated rather than separated.
Pour the wet ingredient mixture from Step 3 into the bowl with the dry ingredients from Step 2. Using a wooden spoon or spatula, fold the ingredients together gently using a scraping motion from the bottom of the bowl upward, just until the dry ingredients are barely moistened and no flour streaks remain. Do not overmix—lumpy batter is actually preferable here, as overmixing develops gluten and makes the bread tough and dense.
Gently fold the squeezed zucchini from Step 2 and most of the pistachios (reserving about 1 tablespoon for topping) into the batter using the same scraping and folding motion. The moisture from the zucchini will help create a tender crumb, while the pistachios add bursts of nutty flavor and texture. I always reserve some pistachios for the top to give the finished loaf a beautiful, professional appearance and ensure flavor in every bite.
Pour the batter into your prepared pan from Step 1, smooth the top gently, and scatter the reserved pistachios (about 1 tablespoon) evenly across the surface. Bake for 35-50 minutes—start checking for doneness at 35 minutes by inserting a toothpick into the center; it should emerge clean or with just a few moist crumbs. Once baked through, let the bread cool in the pan for 10 minutes, then turn it out onto a wire rack to cool completely.