Preheat the oven to gas mark 3/170°C/150°C fan/325°F.
In a mixing bowl, cream the Flora Buttery and sugar together until light and fluffy.
Add the eggs, one at a time, and mix well.
Mix in the milk, vanilla, lemon juice and lemon zest.
Add the flour and baking powder and stir until just combined – don’t worry too much about lumps!
Finally – throw in the blueberry and stir to distribute in the mix.
Divide the mix among 12 muffin cases in a muffin tin (and sprinkle some Demerara on top if you wish).
Bake in a preheated oven at gas mark 3, 170°C/150°C fan/325°F for 30 minutes.