Preheat the oven to 180°C.
In a mixing bowl, sift the flour and baking powder together.
In another bowl, cream the margarine and sugar together until light and fluffy, then add the eggs, one at a time. Combine well. Gently mix in the milk, vanilla and lemon juice.
Add the flour, lemon zest and baking powder. Stir gently until just combined – don’t overmix!
Finally, fold in the blueberries.
Spoon the batter mix into silicon muffin cases or a lined muffin tin).
Bake for approx.25 minutes until golden.
Cool on a wire-rack, then dust with some icing sugar just before serving (if liked).