Preheat the oven to 350 degrees F. Line a 12 cup cupcake pan with paper liners.
In a medium bowl, whisk together the flour, baking powder and salt.
In a large mixing bowl, cream together the butter, oil, and sugar on medium speed until light and fluffy, about 3-4 minutes.
Add the egg, egg yolk, vanilla and orange zest. Beat until well combined, scraping down the sides of the bowl as needed.
In a measuring cup, combine the milk and orange juice.
With the mixer on low speed, alternate adding the flour mixture and milk/OJ mixture, in 3 installments each, beating until just combined (do not overbeat).
Divide the batter evenly between the cups (they should be about ⅗ full) and bake for 17-20 minutes until the tops are lightly golden a toothpick inserted in the center comes out clean.
Transfer the cupcakes to a cooling rack and cool completely before frosting.