Preheat the oven to 350°F. Lightly grease a 9” x 5” loaf pan with cooking spray.
In a large mixing bowl, whisk in oil, sugar, milk, egg replacer and sourdough starter. Mix well until sugar is dissolved. Stir in grated zucchini and set aside.
In a medium mixing bowl, combine flour, salt, baking powder, baking soda, cinnamon and cardamom.
Add the dry ingredients into the wet ingredients and mix until just combined.
Pour the batter into the prepared pan and bake for about 40~45 minutes or until the tester comes out clean. Cool the bread in the pan for 5 minutes, then carefully turn it onto the cooling rack and allow to cool completely before slicing.