Preheat the oven to 170℃ and line your loaf tin with butter and baking paper.

In a large bowl beat the butter, sugar, lemon zest together until combined. Add the oil and mix again. Add the eggs one at a time and beat well using a rubber spatula.

Add most of the flour, all the baking soda, baking powder, salt and vanilla into the butter mixture, fold until almost combined.

Add the remaining flour into the blueberries and add it to the batter. Fold until combined. Add the milk and fold together until smooth. Pour the batter to an 8inch loaf tin. Bake for 40 mins or until the cake has risen, it is golden brown on the top and a tooth pick inserted into the center comes out clean.

Let the cake cool for a bit before removing from the tin and transfer to a wire rack to cool completely. While it cools make the icing by mashing and mixing the blueberries with icing sugar and lemon juice.

Drizzle on top of the cake once cooled. Slice, serve and enjoy.