For the blueberry pancake, first select the blueberries. Preheat the oven to 200 °C.
Mix the milk, egg yolks and flour to a smooth batter.
Beat the egg whites with the salt until very creamy. Gradually add the sugar and continue beating until you have a shiny, snow-white mixture. Fold into the batter.
In a large shallow pan, heat the butter. Pour in the batter, top with the blueberries and bake over medium heat for about 1 1/2 minutes on each side.
Transfer to a baking dish and finish baking in a 200 °C oven for 8-10 minutes.
Remove the blueberry pancake, tear into pieces with 2 forks and sprinkle with powdered sugar. Serve immediately.