Whisk sugar, baking soda, baking powder, and salt together in a medium bowl for about 1 minute.
Add lemon zest, Ole-o olive oil, buttermilk, egg, and orange flower water and whisk vigorously until batter looks smooth and well-emulsified. Sift in cake flour and whisk just until well-combined. Scrape into prepared 8-inch pan with parchment lining. Bake until cake is firm, about 33 minutes. (Pro-tip: A toothpick inserted into the center should come away with a few crumbs still attached)
Cool cake directly in pan, about 10 minutes, then run a butter knife around the edges to loosen. Invert onto a wire rack, peel off parchment, and place cake right side up on a serving platter or cake stand. Serve warm or at room temperature, with some whipped cream and lemon zest.