Olive Oil in Cake: The Portuguese Tradition. Olive oil cakes are a cornerstone of Portuguese baking, most famously the bolo de laranja — a centuries-old orange cake that may date back to the Sephardic Jewish community of the 15th century. Using olive oil instead of butter produces a fundamentally different crumb: more tender, more moist, and with better keeping qualities that actually improve over several days. The key difference in method is that there is no creaming stage — the lift comes entirely from chemical leaveners (baking powder and baking soda), which means the batter must not be overmixed or you will develop gluten and produce a tough, dense result. Fold the wet into the dry until no streaks remain and stop immediately. The batter will look alarmingly liquid compared to a butter cake, but this is correct. Extra virgin olive oil brings a subtle fruity depth that pairs beautifully with citrus, while the higher proportion of liquid ingredients creates that characteristically moist, almost custardy crumb that Portuguese olive oil cakes are loved for.