Preheat the oven to 375°F and line a muffin pan with paper liners or grease it well.

Combine the orange zest with the sugar in a mixing bowl. Press the zest into the sugar, then cream with softened butter until light and fluffy.

Add the large eggs one at a time, ensuring each is fully mixed before adding the next.

Mix in the milk and vanilla extract, stirring gently until combined.

Toss 1 tablespoon of flour with the cranberries. Fold in the remaining flour, salt, baking powder, baking soda, and cinnamon until just combined, then gently fold in the cranberries.

Scoop the batter into the lined muffin pan, filling each cup about two-thirds full. Sprinkle coarse sugar on top.

Bake for 30-35 minutes, or until a toothpick inserted comes out clean. Let cool for a few minutes before serving.