Preheat oven to 350°F (175°C) and grease a 9-inch round cake pan.

In a large bowl, whisk together the flour, sugar, baking powder, cinnamon, and salt.

In another bowl, beat the softened butter until creamy, then gradually add sugar and mix until light and fluffy (3-4 minutes).

Add eggs one at a time, blending them completely. Pour in the milk, mixing until smooth.

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

Fold in the fresh cranberries and orange zest until evenly distributed.

Pour batter into the prepared pan and bake for 35-40 minutes or until golden brown and a toothpick comes out clean.