Preheat your oven to 375°F (190°C) and prepare a muffin tin by lining it with paper liners or greasing the cups.
In a large mixing bowl, whisk together the flour, baking powder, and salt until well combined. Set aside.
Zest both oranges using a microplane, aiming for fragrant, bright orange strips, then juice one orange to extract about 1/4 cup of fresh juice.
In a separate bowl, melt the butter and let it cool slightly. Mix in the sugar, orange juice, and buttermilk until smooth and slightly frothy.
Add the orange zest to the wet mixture and stir well to distribute the bright citrus aroma throughout.
Toss the frozen cranberries in a tablespoon of flour to prevent sinking, then gently fold them into the wet batter, being careful not to crush the berries.
Gradually add the dry ingredients into the wet mixture, stirring gently with a spoon or whisk until just combined; avoid overmixing to keep the muffins tender.
Spoon the batter evenly into the prepared muffin cups, filling each about 3/4 full, allowing room for rising.
Bake in the preheated oven for 20-25 minutes, until the muffins are golden on top and a toothpick inserted in the center comes out clean with a few moist crumbs.
Remove the muffins from the oven and let them cool in the tin for 5 minutes, then transfer them to a wire rack to cool completely or enjoy warm.
Optionally, dust with powdered sugar or drizzle with honey for extra sweetness before serving. Enjoy the bright citrus aroma and juicy cranberries with every bite!
