Preheat oven to 350°F (180°C). Line a 9×5 inch loaf pan with parchment. In a large bowl, rub orange zest into sugar with your fingertips until fragrant. Whisk in flour, baking powder, baking soda, and salt.

In a separate bowl, whisk together orange juice, oil, non-dairy milk, vanilla, and vinegar until smooth.

Pour wet mixture into dry ingredients and fold with a spatula just until no flour streaks remain. Pour batter into the prepared pan.

Bake 50 to 55 minutes until golden and a toothpick comes out clean. Cool 10 minutes in the pan, then transfer to a rack. Whisk powdered sugar with enough orange juice to make a thick but pourable glaze, drizzle over the warm cake, and let it set before slicing.