Place the flour, baking powder and caster sugar into a bowl and stir to combine.
Add the egg yolks and milk to the bowl with the dry ingredients and whisk to make a smooth batter.
In a separate clean bowl, whisk the egg whites until soft peaks form when the whisk is removed, then fold into the batter.
Heat a large frying pan until hot, add the butter and heat until melted and foaming. Place ladlefuls of the batter into the pan and cook for 1-2 minutes, or until bubbles start to form on top of the batter. Turn the pancakes over using a spatula and cook for a further minute on the other side. Remove from the pan and keep warm until ready to serve. Repeat the process with the remaining batter.
Meanwhile, heat a frying pan until hot, add the bacon and cook for two minutes on each side, or until crisp. Remove from the pan and drain on kitchen paper.
To serve, divide the pancakes among four serving plates, top with the bacon and drizzle with maple syrup.