Separate the eggs. Beat with the sugar until frothy. Add the mineral water and yoghurt, stir in the flour and oat flakes. Let the dough stand for a few minutes.
During this time, preheat the oven to 50 °, beat the egg white with a pinch of salt until stiff and fold into the dough.
Heat oil in a large pan. Put the dough for 3 palm-sized cakes in the pan and bake golden yellow on both sides over medium heat.
Place in the oven to keep warm and prepare the rest of the dough in the same way.
Sprinkle with powdered sugar and serve.
Makes about 12-15 cakes.
We also eat fresh seasonal fruits or cherries from the glass. A super light, complete meal in summer.