Blueberry and vanilla cake

1. Pre-heat oven to moderate, 180°C. Lightly grease a 20cm square cake pan. Line base and sides with baking paper.
   
2. In a bowl, whisk together oil, eggs, sugar and vanilla, until thick. Fold in flour alternately with milk, until combined. Pour mixture into prepared pan. Sprinkle with berries.
   
3. Bake for 55-60 minutes, until cooked when tested with a skewer.
   
4. Cool in pan for 10 minutes before turning out onto a wire rack to cool completely. Dust with icing sugar and serve with extra blueberries.