- Position an oven rack to the mid-oven position and preheat the oven to 350°F.  Oil the bottom and sides of a 9-inch round springform pan. A regular 9-inch round cake pan will work too.  Line the bottom with parchment and turn it topside up when you remove the cake from the pan to complete cooling. 
- Whisk flour, baking powder, and salt together in a medium bowl.  Set aside.  Combine the milk and orange juice.  Set aside. 
- Using a handheld electric mixer, beat the eggs on medium speed until foamy, about 1 minute.  Add 1cup of sugar and orange zest, and whip on high speed until the mixture is fluffy and pale yellow, about 2 minutes. 
- Reduce speed to medium, and while mixer is running, pour the olive oil in a slow, steady stream.  Mix until oil is fully incorporated. 
- On low speed, add half of the flour mixture and mix until barely incorporated.  Stop to scrape the sides and bottom of the bowl if needed.  Add the milk-orange juice mixture and mix until combined.  Add remaining flour mixture and mix until just incorporated. Scrape down the bowl as needed. Be careful to not over mix 
- Pour the batter into the prepared pan and sprinkle the remaining 1 tablespoon of granulated sugar evenly over the entire surface.  Bake until the cake is deep golden brown, about 40 – 45 minutes. Test for doneness by inserting a toothpick in the center of the cake.  It should come out with only a few crumbs clinging 
- Transfer the pan to a wire rack and cool for 15minutes.  Remove the sides of the springform pan and cool completely before serving.