Preheat oven to 350 degrees F. Grease a 10-inch cake pan with olive oil.
In a large bowl, whisk together the eggs, sugar, olive oil, milk, Triple sec, orange juice, and zest. In a separate bowl, sift together the cake flour, baking soda, baking powder, and salt. Mix the dry mixture into the wet mixture. Whisk until well blended (the batter will be thin.)
Pour the mixture into the oiled cake pan. Bake for 1 hour. Place on a rack to cool for at least 5 minutes. Run a knife around the edges and turn out onto a plate. Sprinkle with powdered sugar and serve!