Preheat the oven to 350°F (175°C) and grease a 9×5-inch loaf pan, lining with parchment for easy removal.

Whisk all-purpose flour, granulated sugar, baking powder, salt, and ground cinnamon in a large bowl until evenly blended and aromatic, about 30 seconds.

Beat unsalted butter and sugar together until fluffy and pale, about 3 minutes.

Beat in eggs one at a time, then stir in buttermilk and vanilla extract until smooth.

Gently fold wet ingredients into the dry mixture until just combined.

Fold in floured cranberries and fresh orange zest evenly through the batter.

Pour batter into the prepared loaf pan, smoothing the top with a spatula.

Bake at 350°F for 55–60 minutes until the crust turns golden brown and a toothpick in the center comes out clean.

Allow the bread to cool in the pan for 10 minutes, then transfer to a wire rack to cool before slicing.

Optional: Sprinkle coarse sugar on top before baking for extra sparkle.