Preheat the oven to 350°F (175°C) and prepare your cake pan.

In a large bowl, cream together the room-temperature butter and sugar until light and fluffy.

Add the eggs one at a time, mixing until fully absorbed before adding the next.

Stir in the vanilla extract and orange zest until well combined.

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

Gradually combine the dry ingredients with the wet mixture, alternating with the milk, mixing until just combined.

Toss blueberries in a tablespoon of flour then gently fold them into the batter.

Pour the batter into the prepared cake pan and smooth the top.

Bake for 55 to 65 minutes, or until golden brown and a toothpick comes out clean.

Allow the cake to cool in the pan for 10 minutes, then turn it out onto a cooling rack.

Once completely cool, dust with powdered sugar before serving.

Store the cake at room temperature for up to two days or refrigerate for longer freshness.

This cake freezes well; wrap it tightly for up to 3 months, thaw before serving.