Preheat your oven to 175°C (350°F) and grease a 9x5 inch loaf pan. In a large mixing bowl, whisk together the flour, baking powder, and salt until evenly combined.
Using a microplane, zest the orange until fragrant, then juice it to extract about 1/4 cup of fresh orange juice. Set both aside for later.
In a separate bowl, melt the butter until just warm, then whisk in the sugar until the mixture is smooth and slightly fluffy. Add the eggs one at a time, whisking well after each addition, until the mixture is shiny and well combined.
Stir in the orange juice, orange zest, and a little more zest on top if you like for extra aroma. Mix until everything is evenly incorporated.
Gently fold the wet ingredients into the dry ingredients just until combined, being careful not to overmix — a few lumps are fine. This helps keep the bread tender and light.
Rinse the cranberries, then toss them in a tablespoon of flour to prevent sinking. Fold the cranberries gently into the batter, distributing them evenly without breaking them up.
Pour the batter into your prepared loaf pan, smoothing the top with a spatula. Sprinkle a little extra orange zest or sugar on top for a pretty finish.
Bake in the preheated oven for about 50-55 minutes, or until the top is golden brown and a toothpick inserted into the center comes out clean. Your kitchen will fill with a bright citrus aroma as it bakes.
Remove the bread from the oven and let it cool in the pan for 10 minutes. Then, transfer it to a wire rack and cool completely before slicing to allow the crumb to set nicely.
Slice into thick pieces, revealing the juicy cranberries and fragrant citrus crumb. Serve at room temperature for the best flavor and moist texture. Enjoy your vibrant, festive loaf!