Prepare parchment-lined 9x5-inch loaf pan then position rack to centre of oven and preheat to 350ºF (177ºC).
Next, shred your zucchini, taking care to remove any excess moisture, and dice your apple. Set aside.
To a large mixing bowl add eggs, melted butter, brown sugar, yogurt and vanilla and whisk together until smooth. Stir in grated zucchini and diced apple until evenly distributed.
Next, add both flours, baking powder, baking soda, cinnamon, nutmeg, ginger and salt and mix until just combined and no flour bits remain. The batter will be thick.
Transfer batter into prepared loaf pan and smooth the top into an even layer. Evenly sprinkle the 1 tablespoon of turbinado sugar across the top.
Bake for 55-60 minutes until deeply golden and a tester inserted comes out clean. If you notice the sugar crust is getting too dark around the 40-minute mark, simply tent a loose piece of aluminium foil over the top of the pan. Once baked, let bread cool in pan for exactly 10 minutes, then lift it out and place it on a wire cooling rack directly.