Preheat the oven to 350°F and take a 9×5-inch loaf pan or muffin tin and grease it with some vegetable oil.
Combine the grated zucchini, crushed pineapple, granulated sugar, vegetable oil, eggs, and vanilla extract in a large mixing bowl. Use a whisk to blend the ingredients thoroughly.
Mix the flour, baking powder, baking soda, cinnamon, and salt in a separate bowl.
Gently incorporate the dry ingredients into the wet mixture, stirring until combined.
Pour the batter into the greased pan or muffin tin, ensuring the top is smooth.
Place in the preheated oven and bake for between 50 to 60 minutes in a loaf pan or 20 to 25 minutes in a muffin tin, making sure that a toothpick inserted into the center comes out clean.
After 10 minutes, take the bread out of the pan and place it on a wire rack to finish cooling.
Serve the bread as is, or decorate it with cream cheese frosting if desired.