First you need to prepare the base. In a food processor or in a plastic bag using a rolling pin, crush the biscuits crumbs. Add sugar and pour the melted butter. Hands mash nice crumbs, so that the butter to penetrate everywhere and make them wet. In round (my diameter 24 cm) with pendulum bottom insert cut a circle of baking paper and lightly oiled tray walls. Pour the crumbs and they rake it. Take a good push to the bottom to form a strong foundation. Leave it in the refrigerator while you prepare the filling. Turn oven to 170C and start the preparation of the cream cheese. In a large bowl pour the sifted powdered sugar and cream add the feta cheese. With Blades knead lightly two components. Then take a wire whisk and stir until a smooth cream. Pour the cream and mix again. Add the lemon juice and rind. Wrong again. Then add egg, mix it well, and then add the egg yolks. Once everything goes wrong and a homogeneous mixture remove biscuit base from the refrigerator and pour in the filling. Bake 50-60 minutes at medium BBQ, looking to not burn it. Shake a little cake before baking finish. The filling should be gently shaking like jelly in the middle. After the minutes turn the oven off and leave cake inside for at least two hours. It is very important because otherwise there is a danger filling to split and develop the kind of cake. Leave it for 2-3 hours inside and you'll have no problem with that. After this time you can serve immediately or store it in the refrigerator until serving him.