Cold egg whites, beat vigorously together with salt and vinegar. Once they have become a thick foam, add the sugar, vanilla sugar and continue beating, until the sugar mixture liquefies.
After the sugar has melted, add the baking powder and the sifted flour, then mix lightly with a spatula, so that all the flour is incorporated.
Wash the strawberries, clean the stalks and cut them into cubes.
Prepare the muffin trays, lining them with special sheets, or in their slag with a little butter / oil and flour.
Put a polish from the above dough in each form of muffin, then add the pieces of strawberries and cocoa beans / pieces of chocolate, then bake in the preheated oven, approx. 35 minutes at 180 degrees.
After passing the toothpick test, the muffins are removed from the oven, left to cool, then powdered thoroughly with powdered sugar.
Good luck and good luck!