Beat the egg whites until stiff and put it aside.

Stir 2 eggs and two egg yolks with sugar and powdered sugar until fluffy.

Add poppy seed oil, kefir, flour, baking powder and lemon zest to the egg mixture and mix it well with an electric mixer.

Mix carefully the beaten egg-white into the dough.

Pour the dough into buttered and floured muffin cups or a cake pan.

Place the pan / muffin cups into the oven heated for 180ºC / 356ºF for about 25 minutes.

Stick the muffins with a meat pin or a fork before taking them out. If the needle can be easily removed from the cake, your muffin is ready.

Caramelize 3 spoonfuls of sugar in a dry pan. Add the forest fruit.

Add 2 teaspoonfuls of Sour cherry balsamico. Keep stirring the mix on low heat for a while.

Serve it with powdered sugar on top. Enjoy!