Preheat the oven to 350°F (175°C) and grease a 9-inch round cake pan, lining the bottom with parchment if preferred for easy release.

In a bowl, cream the softened butter and sugar with a mixer until pale and fluffy, about 2–3 minutes.

Add eggs one at a time, beating well after each addition. Stir in the orange zest, 2–3 tablespoons orange juice, and vanilla.

In a separate bowl, whisk together the flour, baking powder, baking soda, and salt.

Add the dry ingredients to the wet in three additions, alternating with the milk, beginning and ending with the dry. Mix gently and stop as soon as the flour disappears.

Toss the cranberries with 1 tablespoon of flour (to prevent them from sinking) and fold cranberries into the batter evenly.

Pour the batter into the prepared pan and smooth the top with a spatula.

Bake for 30–35 minutes, until the top is golden and a toothpick inserted in the center comes out clean or with a few moist crumbs.

Cool in the pan for 10–15 minutes, then transfer to a wire rack to cool completely.

Serve slices warm or at room temperature, optionally dusted with powdered sugar or drizzled with a light orange glaze.