Start by greasing two 8 x 4-inch loaf pans or lining them with parchment paper. Preheat your oven to 325°F (163°C).

While the oven heats, wash and grate enough zucchini to yield about a cup. Next, dice your apples into small, bite-sized pieces.

In a large mixing bowl, whisk together the all-purpose flour, ground cinnamon, baking powder, baking soda, and salt until well combined.

In a separate bowl, beat together the eggs, vegetable oil (or applesauce), vanilla extract, and both sugars until the mixture is smooth and creamy.

Gently add your wet ingredients to the bowl containing the dry ingredients. Stir together just until combined.

Carefully fold in the grated zucchini, diced apple, and chopped walnuts into the batter.

Allow the batter to sit for about 5 minutes in the bowl.

Divide the batter evenly between your prepared loaf pans, smoothing the top with a spatula. Bake for 55 minutes.

Once baked, remove the pans from the oven and let them cool for about 20 minutes on a wire rack.