Preheat oven to 350 degrees. Line up a donut tray or muffin tray with paper liners, and set aside.
In a large bowl, combine flour, sugar, salt, baking soda, and baking powder.
Stir with a fork to combine and make a large well in the center.
Pour in orange zest, milk, vanilla extract, eggs, and oil into the well and stir until just combined.
Spoon into prepared tins to be 3/4 full and bake 12 to 15 minutes for donuts. For cupcakes bake for about 18 minutes. Cool completely before frosting.