Preheat your oven to 375°F (190°C) and prepare a muffin tin by greasing it lightly or lining it with muffin cups.

In a large bowl, mix together flour, sugar, baking powder, and salt until combined.

In another bowl, whisk melted butter, eggs, milk, orange zest, and juice until smooth.

Pour the wet mixture into the dry ingredients and fold gently until just combined.

Carefully mix in cranberries until evenly distributed.

Fill each muffin cup about two-thirds full with batter and bake for 20-25 minutes or until golden brown and a toothpick comes out clean.

Let cool slightly before transferring to a wire rack.