Preheat oven to 350 degrees. Spray 3 8-inch round cake pans with baking spray, line bottoms with parchment rounds and spray again, set aside.
In the bowl of a stand mixer, rub the orange zest into 1 ½ cups of the sugar until fragrant and blended.
In a separate bowl, whisk together the flour, baking powder, soda, and salt. Set aside.
Cream together the orange sugar, butter, and oil until light and fluffy, about 5 minutes. Mixture should be pale white. Scrape down sides of bowl and necessary.
Add eggs to sugar mixture one at a time, mixing until fully incorporated. Stir in vanillaand the orange extract scraping down sides of bowl again.
Working in three batches, add the dry ingredients to the wet ingredients, alternating with milk, ending with flour. Scrape down the sides of bowl after each addition of flour, being sure batter is thoroughly mixed.
Evenly distribute batter among prepared pans. Bake in preheated oven for 35 minutes, or until cakes have risen and begun to pull away from sides, and a tester inserted into the center comes out clean. Remove from oven and allow cakes to cool in pans, on wire racks, for ten minutes. Turn cakes out of pans and cool to room temperature.