Preheat your oven to 180 °C (350 °F) and prepare your loaf pan by greasing it with butter or oil.

In a large mixing bowl, whisk together the eggs and sugar until light and fluffy. Add the vegetable oil and vanilla extract, mixing well.

Fold in the grated zucchini until evenly distributed.

In a separate bowl, sift together the flour, baking powder, baking soda, salt, and ground cinnamon.

Gradually add the dry ingredients to the wet mixture, stirring gently until just combined. Avoid overmixing.

If using, fold in the chopped nuts or chocolate chips at this stage.

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.

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

Serve warm or at room temperature, optionally with butter or cream cheese.