Preheat your oven to 350°F (175°C). Grease a 9x5-inch loaf pan well or line it with parchment paper.

Grate about 2 cups of zucchini using a box grater. Place the grated zucchini in a clean kitchen towel and squeeze gently to remove excess moisture.

In a large bowl, whisk together the whole wheat flour, oat flour, baking soda, baking powder, cinnamon, and salt.

In a separate bowl, beat the eggs with the Greek yogurt, maple syrup (or honey), and vanilla extract until smooth and well combined.

Fold the squeezed zucchini into the wet mixture gently until evenly distributed.

Gradually add the dry ingredients to the wet zucchini mixture, folding gently with a spatula just until combined. Be careful not to overmix.

If using, fold in the chopped almonds and/or dark chocolate chips or raisins.

Pour the batter into the prepared loaf pan and smooth the top with a spatula.

Bake for 50 to 60 minutes, or until a toothpick inserted into the center comes out clean. If the top browns too quickly, tent loosely with aluminum foil.

Let the bread cool in the pan for 10 minutes, then turn it out onto a wire rack to cool completely before slicing.