Pre-heat oven at 180o C. In a bowl place the flour with the baking powder and leave to one side. Cream together in the mixer the Margarine, Butter and Sugar. Add one egg and mix for about 3 minutes then add the remaining egg mixing for another 3 minutes.
Step 1: In a bowl, mingle the flour, the baking powder, the baking soda and the salt and leave it aside. Step 2: In another bowl mingle the espresso coffee, the liquid vanilla and the yoghurt.
Cut the chocolate into small pieces and melt in bain marie. When the chocolate is thoroughly melted take off the heat and leave to one side. Whisk the egg whites either by hand or with a mixer until they form a meringue - soft like peaks.
Add in the mixer bowl the egg whites and the crystal sugar. Start the eggs whisk in medium speed for about 15 minutes until it gets fluffy. In the meantime, you can sift the powdered sugar.
Having the butter in about 25 degrees, apply it on a baking dish for baklava. Spread 15 pastry sheets, one over another, in the buttered baking dish. Sprinkle with some melted butter between the pastry sheets.