For best results, ensure the zucchini is thoroughly squeezed dry to prevent a soggy cake. Fresh or frozen blueberries can be used. If using frozen, do not thaw them before adding to the batter. Lecithin granules act as an emulsifier and help to create a more tender crumb, but they can be omitted if unavailable. Store the cake in an airtight container at room temperature for up to 3 days.