Preheat oven to 350°F and grease a 9 x 5-inch loaf pan.
In a medium bowl, whisk together flour, baking powder, and salt.
In a separate small bowl, mix sugar and orange zest until sugar lightens in color.
In a large bowl, whisk buttermilk, oil, orange juice, eggs, and vanilla.
Add flour mixture and orange zest sugar to wet ingredients; whisk until just combined without overmixing.
Fold in fresh cranberries using a wooden spoon or spatula.
Pour batter into prepared loaf pan and bake for 65-75 minutes; cover loosely with foil if browning too fast.
Check doneness with toothpick; let cool 10-15 minutes in pan, then transfer to cooling rack.
To make the glaze, whisk powdered sugar and orange juice until smooth and creamy; adjust consistency as needed.
Once bread is completely cool, drizzle glaze over top, slice, and serve.