Chopped biscuits in a mortar is possible to finely. Margarine melts together with the butter and smeared round pan with a diameter of about 30 cm. Pour crushed biscuits in the tin and pour on top evenly with the rest of the melted butter. In a separate bowl whisk eggs with sugar, gradually add the yogurt and the feta cheese. This mixture was poured uniformly on the slightly depressed biscuits. Bake in preheated oven at 180 C about 40-50 minutes. Check with a toothpick. Finally, it remains to cool a bit and smeared with jam. Cool before serving. * To crushed biscuits can be added and some crushed walnuts. * It is normal to become top brown, almost black. As I pull him leave to cool and then turn it on a plate and then in another bowl, to be with cookies below, but be careful if hot to not adhere to the plate.