Position a rack in the middle of the oven, and preheat to 350°F (175°C). Make sure no other racks are in the way, so the heat circulates evenly. Coat a 12-cup bundt or tube pan with nonstick baking spray to ensure your cake comes out perfectly.
Finely grate the zest of 3 of the oranges and squeeze the juice from 4 of them into a measuring cup. You should aim for about 1½ cups of juice. If you don’t have enough, squeeze the fifth orange. This fresh juice is key to the cake’s flavor.
In a large bowl, whisk together the flour, baking powder, and kosher salt until well combined. This step helps distribute the leavening agent evenly throughout the mixture.
In a stand mixer fitted with a paddle attachment, or using a handheld mixer in a large bowl, beat the eggs on medium-high speed for about 1 minute until well combined. Slowly add in the granulated white sugar, continuing to beat until the mixture is thick and pale yellow, which should take about 3 minutes.
Reduce the speed to low and begin adding the flour mixture and olive oil alternately, starting and ending with the flour. Mix until just a few wisps of flour remain visible. This method helps to create a light, airy batter.
Pour in the orange juice and zest, then whirl the mixture for a few seconds until the batter comes together smoothly. The batter should be velvety and lightly orange in color.
Carefully pour the batter into the prepared pan, smoothing the top to ensure an even bake. Bake in the preheated oven until a cake tester comes out with a few moist crumbs clinging to it, which should take about 1¼ hours. If the top begins to brown too much, lightly cover it with foil.
Once baked, transfer the pan to a wire rack and cool for 15 minutes. This cooling period allows the cake to set slightly, making it easier to remove from the pan.
After 15 minutes, turn the cake out onto the rack and allow it to cool completely. For the best flavor, place the cooled cake in a covered cake stand and let it sit overnight. This resting period allows the flavors to deepen and meld.
Just before serving, dust the top of the cake with powdered sugar for a beautiful presentation. Enjoy each slice knowing it’s made with love!