Preheat the oven to 200C (400 F, Gas Mark 4)
Sift the flour and baking soda into a bowl
Add the sugar into the bowl and mix together
Melt the butter in a saucepan and pour into the flour and sugar mixture.
Add the eggs, vanilla essence, and yoghurt and stir until they are just combined.
Add the blueberries and stir gently until the blueberries are distributed through the mixture.
Divide the mixture between 12 muffin cases and place on a baking tray. You may get more or less muffins depending on the size of the muffin cases.
Bake in a pre-heated oven at 200C (400 F, Gas Mark 4) for 15 minutes until the tops have cracked and turned golden brown.