Pre-heat the oven to 180°C.
Cream together the butter and sugar.
Sift together the dry ingredients.
Whisk the eggs and add to the butter mixture, stirring to combine.
Add the zest and juice of the lemon and mix to combine.
Toss the blueberries in the flour mixture and put to one side.
Slowly add the flour mixture, stirring to combine.
Add the floured blueberries and mix.
Spoon into loaf tin and bake for 25 minutes or until golden brown.
Leave to cool before serving.