Soak gelatin in 200 grams of cold drinking water for about an hour. You can use both domestic granulated gelatin and the imported sheet one. Prepare a rich-whipped semi-finished product. Whip sugar together with butter with a wire whisk until smooth. Add the eggs and stir. Add sifted flour and stir again. The consistency of the dough should look like sour cream, just a more viscous. Cover the baking pan with a cooking sheet, grease with butter and spread the resulting mass with a layer of 0.5 cm. Preheat the oven to 250-270 °C. Bake for 5-7 minutes until gold. Cool the ready dough and cut two identical rectangles (or circles, or squares – at your pleasure) out of it. Combine 460 g sugar and 150 g water. Bring to the boil, slack the fire. Add citric acid. Cook for 30-40 minutes under a low heat, stirring until the syrup becomes slightly viscous. If raising the spoon with the syrup from the pan, the syrup "thread" should not break. Add gelatin and stir. As the mixture begins to thicken, remove it from fire. For the milk protein cream (souffle), beat up white of eggs with mixer. They should expand four-five times. Slowly pour the syrup into the white of eggs and whip again. Allow the resulting mass to stand at room temperature for 5 minutes. Whip butter with a wire whisk until white. Add condensed milk and stir to the sour cream consistency. Add butter with condensed milk to the protein mass. Stir with a mixer. Put a loose bottomed cake tin on a cooking sheet, laying a cutting board under it. Put the pie shell in the cooking sheet. Cover it evenly with milky protein cream, leaving about 100 g of mass. Put the second pie shell. Distribute the remaining cream. Cool in the refrigerator at -3 °C for 10 minutes. For the glaze, melt chocolate on a boiling-water bath, gently stirring. If the chocolate mass is very thick, add butter. When chocolate finally melts, get the pan with souffle out of the refrigerator and pour it over with chocolate glaze. Refrigerate the pan again. Remove the cake tin from the ready ptichye moloko. You can dress the cake with a creamy fondant, butter cream or chocolate and serve just after the dressing (if you want the mass to be tender), or you can refrigerate it for another 24 hours. In this case the souffle will become more porous.