Preheat oven to 350˚F. Butter and flour a 9x5-inch loaf pan, and set aside.
In a large bowl, whisk together the flour, brown sugar, baking powder, baking soda, and salt. In a medium bowl, whisk together the melted butter, egg, and milk. Add the wet mixture to the dry mixture and fold to combine. Fold in the cranberries.
Pour the batter into the prepared loaf pan and sprinkle with turbinado sugar. Bake 1 hour and 15 minutes, until a toothpick inserted into the center comes out clean. Allow to cool in pan on a wire rack for 30 minutes, then remove from pan and place on wire rack to cool completely.