Preheat the oven to 350 degrees F. Line a standard loaf pan (9 x 5 inch) with parchment paper or spray with oil.
In a large bowl, add the oil, almond milk, ground flaxseeds, brown sugar and vanilla. Whisk well until combined.
Lightly blot the grated zucchini with paper towels, and add it to the bowl. Stir the zucchini into the wet ingredients.
Now add the flour to the wet ingredients. Sprinkle the baking powder, baking soda, salt and cinnamon on top of the flour. Stir gently until just combined, being careful not to over mix, or your loaf will be dense.
Fold in the walnuts or chocolate chips, if using. Pour into the prepared pan, and bake for 45-55 minutes, or until a toothpick inserted in the center comes out clean.
Let it cool in the pan for a few minutes, then transfer the loaf to parchment paper or a cooling rack. Slice carefully right away, or let cool completely for easier slicing and serving.