Sieve the flour and baking powder into a bowl and make a well in the middle.
Place the yolks and the milk into the well in the flour mixture, and whisk to create a smooth batter. The batter should be the consistency of double cream. Add a little extra milk if necessary, although you may not need it all.
Whisk the egg whites in a clean bowl with a pinch of salt, until stiff peaks form when the whisk is removed.
Fold the egg whites into the batter.
Heat a heavy non-stick pan over a medium heat and brush it with some vegetable oil.
Pour two tablespoons of the batter into the pan, smoothing it out into a circle. Cook for one minute, or until bubbles start to form on the surface, then add a handful of blueberries, and cook for another minute. Turn the pancake and cook the other side for one minute, or until golden-brown. Remove from the pan and reserve in a warm place.
Repeat with the remaining batter and berries and serve immediately.
