This cake highlights the fruit-forward qualities of the olive oil, while balancing out the citrus notes from the lemon. You can substitute a different citrus fruit, or even add some fresh herbs to make this cake yours — I love adding some fresh lemon thyme and serving it with a dollop of yogurt. — Maria Loi and Sarah Toland, The Greek Diet
Preheat the oven to 350 degrees F. Coat a 9-inch springform pan with a little olive oil. Cut a round of parchment paper to fit the pan, place it on the bottom of the pan, and coat it liberally with some olive oil.
In a small bowl, whisk together the flour and lemon zest. Set aside.
In a medium bowl, with an electric mixer or an egg beater, beat the 5 egg yolks and ½ cup of the sugar on high speed until the mixture is thick and pale, 3 to 4 minutes. Reduce the speed of the mixer/beater to medium-low and slowly add the 1 cup olive oil and the lemon juice, mixing them until just combined. The batter might look as if it has separated, but that’s okay! Using a wooden spoon, mix in the flour mixture just until combined. You don’t need the electric mixer for this step.
In another bowl, with the electric mixer or the egg beater, beat the 4 egg whites with the salt at medium to high speed until foamy. Continue to beat as you slowly add the ¼ cup sugar, and keep beating until soft peaks form, 3 to 4 minutes.
Carefully fold about one-third of the beaten egg whites into the batter and then gently but thoroughly fold in the rest of the egg whites.
Transfer the batter to the prepared cake pan and gently rap the pan against a hard surface to release any air bubbles that may have formed during the mixing process. Sprinkle the top of the cake with the remaining 1 ½ tablespoons sugar.
Bake the cake until it rises, is a beautiful shade of gold, and a toothpick inserted into the center of the cake comes out clean, with no traces of uncooked batter, about 45 minutes.
Allow the cake to cool in the pan on a rack for 10 to 15 minutes. Run a knife around the edges of the pan and release the springform sides. Let the cake cool and rest for another hour. Flip the cake over onto a plate. Remove the bottom of the pan and the parchment paper.