Heat the oven to 180°C and line your muffin tin with paper cups. In a large bowl combine together the flour, sugar, baking powder and salt and then set aside. In a smaller bowl whisk together the milk, oil, eggs, lemon zest and vanilla. Add this to the dry mixture and stir very gently being careful not to overwork. Add in the blueberries and fold into the batter being careful not to break up the blueberries. Stir just enough to evenly distribute the blueberries throughout the batter. Divide the batter evenly between the cups.
Bake for 18 – 25 minutes until the tops are golden brown. Move to a wire rack to completely cool. If you aren’t planning to eat these straight away, I recommend freezing and pulling out of the freezer as required.