Mix 3 eggs, milk and salt. Add flour and baking powder bit by bit and mix to a smooth dough. Cover and let stand for about 30 minutes. In the meantime, sort out blueberries, wash and drain well. Stir mineral water into the pancake batter. Heat a little fat in a large pan and pour in some batter.
Sprinkle generously with blueberries and bake at medium heat for 11/2-2 minutes. Turn the pancakes, finish baking and turn them over on a board with the fruit side up. Sprinkle with 1 tablespoon of sugar and allow to cool slightly. Bake about 5 pancakes one after the other and roll them up at the end. Cut the rolls diagonally into slices. Grease a large, flat casserole dish and place the slices in flakes. Separate the remaining eggs. Beat the egg white until stiff. Cream egg yolk, remaining sugar (approx. 50 g) and vanillin sugar. Stir in the quark and lemon peel. Finally fold in the beaten egg white.
Grease a large, flat casserole dish and place the slices in flakes. Separate the remaining eggs. Beat the egg white until stiff. Cream egg yolk, remaining sugar (approx. 50 g) and vanillin sugar. Stir in the quark and lemon peel. Finally fold in the beaten egg white. Pour the quark foam as a topping over the rolls and bake in the preheated oven (electric cooker: 225 ° C/ gas: level 4) for approx. 10 minutes. Serve dusted with icing sugar