Preheat the oven to 350°F (175°C). Before baking, prepare a 9x5-inch loaf pan by either thoroughly greasing it or lining it with parchment paper to ensure the loaf can be easily removed.

Mix the dry ingredients: In a large bowl, whisk together the flour and baking powder. Set aside.

Prepare the wet ingredients: In another bowl, combine the sugar and orange zest, rubbing them together with your fingers to release the oils from the zest for a more vibrant flavor. Add in the melted butter, eggs, buttermilk, vanilla extract, and orange juice. Whisk until well combined.

Combine the mixtures: Gradually add the dry ingredients to the wet mixture, stirring just until incorporated. Be careful not to overmix, as this could result in a dense loaf.

Fold in the cranberries: Gently fold the chopped cranberries into the batter, ensuring even distribution.

Bake: Transfer the batter into the lined or greased loaf pan, ensuring the surface is even. Place it in the preheated oven and bake for 55 to 60 minutes. To check for doneness, insert a toothpick into the center; it should come out clean when the loaf is ready. If the top starts to brown too quickly, loosely cover with foil during the last 15 minutes of baking.

Make the glaze: While the bread is cooling, whisk together the powdered sugar, orange juice, and orange zest in a small bowl until smooth.

Glaze the loaf: Once the bread has cooled for about 10 minutes, remove it from the pan and place it on a wire rack. Drizzle the glaze over the top of the loaf and let it set before slicing.