1Beat the egg yolks with the sugar until the mixture is creamy and white is.
2Then add the flour with yeast, yogurt, softened butter and orange zest, ... clicking alles.
3Beat the egg whites with a pinch of salt until stiff.
4Add this carefully at the previous mass.
5Then add the chocolate chips.
6Finally,, Grease baking pan and sprinkled with flour.
7Pour the mixture into the tin (Half fill, since this goes double quantity).
8Place in preheated oven at 180 º for about 30 minutes.